How do we install old version of any app
I am looking to install old version of app as new app has some bugs which affecting my daily tasks
iPhone 12 Pro Max, iOS 15
If you have iOS 15 and higher (your Profile says so) installed and the App developer has released an app compatible with the iOS then I don't think you will be able to install an earlier version of the app.
If you are experiencing any difficulty with third-party apps then please contact the app developer directly --> How to contact an app developer - Apple Support
If you have a lower iOS version on your device then please ask the App developer to release the app for lower iOS versions like Netflix.