Azure and Microsoft 365 (Teams/SharePoint/Exchange Online/etc) are best considered separate applications. The only common factor between them is the identity provider, Entra ID/Azure AD. Fundamentally speaking, as long as the Azure subscriptions are set up on the same parent tenant as the users who have the licenses for the M365 services, that is all the integration that there is to do*.

*This is to say, that there is a lot more work to do for a combined Azure/M365 tenant to meet enterprise information security and other such requirements, but the foundation for this is having a single tenant that contains both your users and Azure subscriptions.