I have a Powershell script which runs to set up Azure web apps, databases, etc. but before running the script, I have to do the following:
PS C:/> Login-A
Well, you don't have permissions to assign that role to that serviceprincipal, you need appropriate rights. And those would be: Microsoft.Authorization/roleAssignments/write and scope /subscriptions/5ba06de5-xxxx-zzzz-yyyy-27f7d2c8bba6
You could either create a new Custom Role and assign it to your account, or assign something like Subscription Admin (not sure if its the least possible approach, but you can retract it later) to your account.