Hi Sumaira ,
Is the "Allow" option still greyed out? We would want to be able to allow the connections on the app . This will help us in assigning
the right permissions .
Lets do this one more time .
1.Access Make.powerapps.com
2.Under Data connections - remove all the old connections that exist .
3. Once connections have been deleted - close all browsers - close everything . Now access the powerapp and check if you get the option to "Allow"
If it is still greyed out i would request you to check if you have access to all the resources like sahrepoint site , outlook etc .
If the allow is still greyed out after checking all the permissions are present I would suggest you to please raise a request with MSFT support team to work on the issue by using the link below
https://powerapps.microsoft.com/en-us/support/
Please mark my answer as verified if you found it helpful. Please let me know if you have any other questions around the above.
Bhartendu Pandey
Support Engineer - Customer Engagement- Dynamics CRM/PowerApps/Power Automate
Microsoft