Outlook add-in not visible in ribbon

Hi,

I have developped a outlook add-in using this documentation.
I can install my add-in and it works fine from menu access but I want to display a button in ribbon.
I don't understand why my add-in is not visible in ribbon.

I also tried this example : https://github.com/OfficeDev/outlook-add-in-command-demo but the add-in is also not visible in ribbon

has anybody an idea to help me ?

here is my manifest.xml file

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>  
<OfficeApp xmlns="http://schemas.microsoft.com/office/appforoffice/1.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:bt="http://schemas.microsoft.com/office/officeappbasictypes/1.0" xmlns:mailappor="http://schemas.microsoft.com/office/mailappversionoverrides/1.1" xsi:type="MailApp">  
    <Id>62101ef7-5f83-4c42-a5f8-406b400db608</Id>  
    <Version>2.0.0</Version>  
    <ProviderName>Swizi</ProviderName>  
    <DefaultLocale>en-US</DefaultLocale>  
    <DisplayName DefaultValue="Booking Options - Local version "/>  
    <Description DefaultValue="The Island Booking options - Local version "/>  
    <IconUrl DefaultValue="http://localhost:3000/pr/addon/icon-32.png"/>  
    <HighResolutionIconUrl DefaultValue="http://localhost:3000/pr/addon/icon-80.png"/>  
    <SupportUrl DefaultValue="https://localhost:3000/index.html?appId=5e5fac629e89794ccad4eb9d"/>  
    <AppDomains>  
        <AppDomain>swizi.io</AppDomain>  
    </AppDomains>  
    <Hosts>  
        <Host Name="Mailbox"/>  
    </Hosts>  
    <Requirements>  
        <Sets>  
            <Set Name="Mailbox" MinVersion="1.8"/>  
        </Sets>  
    </Requirements>  
    <FormSettings>  
        <Form xsi:type="ItemRead">  
            <DesktopSettings>  
                <SourceLocation DefaultValue="https://localhost:3000/index.html?appId=5e5fac629e89794ccad4eb9d"/>  
                <RequestedHeight>420</RequestedHeight>  
            </DesktopSettings>  
        </Form>  
    </FormSettings>  
    <Permissions>ReadWriteMailbox</Permissions>  
    <Rule xsi:type="RuleCollection" Mode="Or">  
        <Rule xsi:type="ItemIs" ItemType="Appointment" FormType="ReadOrEdit"/></Rule>  
    <DisableEntityHighlighting>false</DisableEntityHighlighting>  
    <VersionOverrides xmlns="http://schemas.microsoft.com/office/mailappversionoverrides" xsi:type="VersionOverridesV1_0">  
        <VersionOverrides xmlns="http://schemas.microsoft.com/office/mailappversionoverrides/1.1" xsi:type="VersionOverridesV1_1">  
            <Requirements>  
                <bt:Sets DefaultMinVersion="1.8">  
                    <bt:Set Name="Mailbox"/>  
                </bt:Sets>  
            </Requirements>  
            <Hosts>  
                <Host xsi:type="MailHost">  
                    <DesktopFormFactor>  
                        <SupportsSharedFolders>true</SupportsSharedFolders>  
                        <FunctionFile resid="SwiziExtension.Url"/>  
                        <ExtensionPoint xsi:type="AppointmentOrganizerCommandSurface">  
                            <OfficeTab id="TabDefault">  
                                <Group id="msgAppointmentOrganizerGroup">  
                                    <Label resid="GroupLabel"/>  
                                    <Control xsi:type="Button" id="msgReadOpenPaneButton">  
                                        <Label resid="SwiziExtensionButton.Label"/>  
                                        <Supertip>  
                                            <Title resid="SwiziExtensionButton.Label"/>  
                                            <Description resid="SwiziExtensionButton.Tooltip"/>  
                                        </Supertip>  
                                        <Icon>  
                                            <bt:Image size="16" resid="Icon.16x16"/>  
                                            <bt:Image size="32" resid="Icon.32x32"/>  
                                            <bt:Image size="80" resid="Icon.80x80"/>  
                                        </Icon>  
                                        <Action xsi:type="ShowTaskpane">  
                                            <!-- <TaskpaneId>Office.AutoShowTaskpaneWithDocument</TaskpaneId> -->  
                                            <SourceLocation resid="SwiziExtension.Url"/>  
                                            <SupportsPinning>true</SupportsPinning>  
                                        </Action>  
                                    </Control>  
                                      
                                </Group>  
                            </OfficeTab>  
                              
                        </ExtensionPoint>  
                    </DesktopFormFactor>  
                </Host>  
            </Hosts>  
            <Resources>  
                <bt:Images>  
                    <bt:Image id="Icon.16x16" DefaultValue="http://localhost:3000/pr/addon/icon-16.png"/>  
                    <bt:Image id="Icon.32x32" DefaultValue="http://localhost:3000/pr/addon/icon-32.png"/>  
                    <bt:Image id="Icon.80x80" DefaultValue="http://localhost:3000/pr/addon/icon-80.png"/>  
                </bt:Images>  
                <bt:Urls>  
                    <bt:Url id="SwiziExtension.Url" DefaultValue="https://localhost:3000/index.html?appId=5e5fac629e89794ccad4eb9d"/>  
                </bt:Urls>  
                <bt:ShortStrings>  
                    <bt:String id="GroupLabel" DefaultValue="Swizi"/>  
                    <bt:String id="SwiziExtensionButton.Label" DefaultValue="Booking Options - Local version "/>  
                </bt:ShortStrings>  
                <bt:LongStrings>  
                    <bt:String id="SwiziExtensionButton.Tooltip" DefaultValue="Booking Options"/>  
                </bt:LongStrings>  
            </Resources>  
        </VersionOverrides>  
    </VersionOverrides>  
</OfficeApp>