How to delete a customer from the Avanan MSP Dashboard
Partner admin access to the Avanan MSP Dashboard
In the MSP Dashboard, browse for and find the customer that you want to delete.
Click the three dots at right, and from the drop down, choose delete.
The portal will request you to enter the word 'delete' as confirmation, then click Delete.
The customer should disappear from the list.
To fully remove Avanan from the Microsoft 365 service, you should also follow the guide in this article