To install Microsoft SQL Azure Migration Wizard you need a very specific version of Microsoft.Sqlserver.SMO (Version 12 of server management objects)
This library needs to be installed in your global assembly cache (c:\windows\assembly\) in order to work properly and for the azure migration tool to pick it up.
To install every version of Microsoft.Sqlserver.smo plus the other libraries, you can install the SQL Server Data Tools package, which is here: https://docs.microsoft.com/en-us/sql/ssdt/download-sql-server-data-tools-ssdt?view=sql-server-ver15
You can find the source code for the SQL Azure Migration Wizard here: https://github.com/adragoset/SQLAzureMigration
I've been using version 5.15.6.0 of the Migration tool.
