Hello @Slickrc23 ,
Thank you for posting here.
We can check prerequisites based on the information in the following link and establish trust as below:
- Prerequisites
- Sign in to the Azure portal
- Configure DNS in an on-premises AD DS environment to support Azure AD DS connectivity
- Create a one-way inbound forest trust in an on-premises AD DS environment
- Create a one-way outbound forest trust in Azure AD DS
- Test and validate the trust relationship for authentication and resource access
For more information, we can refer to the following link.
Tutorial: Create an outbound forest trust to an on-premises domain in Azure Active Directory Domain Services
https://video2.skills-academy.com/en-us/azure/active-directory-domain-services/tutorial-create-forest-trust
Other information for your reference.
Tutorial: Create and configure an Azure Active Directory Domain Services managed domain with advanced configuration options
https://video2.skills-academy.com/en-us/azure/active-directory-domain-services/tutorial-create-instance-advanced
Hope the information above is helpful.
Best Regards,
Daisy Zhou