Please find the below steps and screenshot to set up the modern authentication. I've attached a document to this solution article that elaborates on the change at Microsoft end and also the steps to switch to Modern authentication.


Step 1: Kindly navigate to Microsoft 365 admin center.

 

Step 2: Click on Settings

 

Step 3: Select Org settings

 

Step 4: Search Modern authentication by using CTRL + F

 

Step 5: Select Modern authentication 

 

Step 6: Turn on the modern authentication

 

Step 7: Save