Gii tool with Yii2.0.45 and php 7.4.29

Do you have a controller named PharmacyController under backend/controllers?
If you have, does it have actionIndex? All these I assume there was no change to defaultRoute for that specific controller

This correct …all PharmacyController is in the backend/controllers directory and the actionIndex and other default actions generated by the Gii tool exist.

Can you create a small project and upload to github that have the problem?
I have run out of ideas and unless I can see the code I don’t think I have any more help to offer

Perhaps check that namespace and PharmacyController class declarations are correct in PharmacyController.php ?