In order for your Apple app to remain available for sale in the Apple app store, there will be a periodic requirement from Apple where you have to accept their Terms and Agreements.
This is a very crucial step as your app will stop working correctly if you don't accept the new terms and agreements.
The steps are very easy and you can do this in less than 2mins. Here's a quick demonstration:
Steps in accepting the new contract:
1. Click on: https://appstoreconnect.apple.com/agreements/#/
2. You will see the new agreement, please review and accept it. It will look like this:
3. Click also here: https://developer.apple.com/account/resources/certificates/list to identify if there is any pending agreement there too.
You will see one line per agreement. All lines need to show "Active" in the "Status" column. If all look "Active", congratulations! you have already accepted all necessary contracts.
If you see one contract that is not active, please click on it and accept it.