The first thing you should do is verify the log rate of your SQL Server instance is too high to consider a migration to an Azure Managed Instance. Nobody does this test and some get surprises once all is migrated. Compare the log rate of your SQL Server instance with the log rate limits for Azure Managed Instance using the procedure outlined in this article.
In addition, perform an assessment using Data Migration Assistant this tool may uncover more challenges for your migration project.
Here you will find more tools to perform assessments and identify blocking points. If you use Data Migration Service (DMS) you will need to open quite some ports to be able to use it, that may be a challenge. maybe a network admin is needed to help on that. DMS is practically the the way to migrate a database in near real-time.