Hi anonymous user,
Some browsers, such as Internet Explorer 11, Safari, and Firefox, support the Microsoft Teams web app but don't support some of the Teams calling and meeting features. You'll find more information here: https://video2.skills-academy.com/en-us/microsoftteams/unsupported-browsers
Here's also some more information that may be helpful:
Join a Teams meeting on an unsupported browser
https://support.microsoft.com/en-us/office/join-a-teams-meeting-on-an-unsupported-browser-daafdd3c-ac7a-4855-871b-9113bad15907
If you have any feedback, I suggest you post it over at the dedicated Microsoft Teams uservoice page over here:
https://microsoftteams.uservoice.com/
There's also an existing uservoice feedback about making Safari supported for Teams Web in the link below which you may give your vote on:
https://microsoftteams.uservoice.com/forums/555103-public/suggestions/18981217-make-teams-web-app-available-in-safari
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(If the reply was helpful please don't forget to upvote or accept as answer, thank you)
Best regards,
Leon