In the master database

CREATE LOGIN [<my-user>@<my-domain>.com] FROM EXTERNAL PROVIDER
CREATE USER [<my-user>@<my-domain>.com]  FOR LOGIN [<my-user>@<my-domain>.com] 

In the database that needs to be accessed

 CREATE USER [<my-user>@<my-domain>.com]  FOR LOGIN [<my-user>@<my-domain>.com] -- Yes. Again
 EXEC sp_addrolemember 'db_datareader', [my-user@<my-domain>.com]