In the left menu Click on Identifiers and after that click on the Plus Icon(blue color) . Click on Continue for the next 2 pages.
Enter Description and Bundle ID for the App ID. (The Bundle ID is best when it’s a reverse-dns style string.)
In the Capabilities section scroll down and select sign with apple. Click on Edit and select Enable as a primary App Id and click on Save. Click on Continue and then click on Register.
In the right corner click on Continue and after that Register button.
Again click the Plus icon( blue color). Select Service IDs and click on Continue.
Enter Description and Identifier( Identifier would be your client id - Copy this id and Paste in the above field of Client ID). and click on the Continue and after that Register button.
Click Keys from the left menu.Click on the Plus icon to register a new key.
Give your Key a name, and select Sign In with Apple and click on Configure button
Select your Primary Id and click on the Save button and after that at the right corner click on Continue and Register button.
Click on the Download button once the key is downloaded click on the Done button.
In the left menu click on Identifiers.
At the right top click on App IDs
Select Service IDs from the drop down menu.
Select your Service Id from the List.
Select Sign In with Apple and click on Configure button
Select the Primary App Id from the drop down, and Enter the Domain and Redirect URL in Domains and Subdomains and Return URLs respectively and click on the Next button (You will get the Domain name and Redirect URL from miniOrange plugin)
Verify the details and click on the Done button. After that at the right corner click on the Continue button.
Copy the Identifier value and click on the Save button.
Enter the Identifier value in the App Id field and copy the downloaded key value in App secret field of the miniOrange social login plugin.
Step 2: Set credentials in miniOrange Social Login Plugin
Copy the Client Id and Client Secret form above setup and Paste them into the fields in Instructions.
Then click on Save & Test Configuration button.
Custom app will set properly when Test configuration get successful.