Access your Apple developer account

1. Go to the  Apple developer portal.
   
2. Sign into your Apple developer account.

Generate an App ID

3. Choose Identifiers under the Certificates, Identifiers & Profiles section.
   
4. In the Identifiers page, click the blue plus icon.
   
   
5. Choose App IDs and click Continue.
   
   
6. Select App.
7. On the next screen, you’ll have to enter a description and Bundle ID for the App ID.
   
   
8. Then scroll down through the list of capabilities and check the box next to Sign In with Apple.
   
9. Click Register. 

Generate Services ID

Note: The Service ID can only contain alphanumeric characters and dots. 

10. In the Certificates, Identifiers & Profiles page, choose Identifiers from the side navigation and click the blue plus icon next to Identifiers.
    
11. Choose Services IDs and click Continue.
    
    
12. On the next screen, you’ll need to enter a description and identifier for the Services ID. The Service ID can only contain alphanumeric characters and dots.
    
    
13. Click Register.
14. Then check the box next to Sign In with Apple.
    
15. Click the Configure button.
    
16. In the Web Authentication Configuration popup, enter the Redirect URI copied from Zoho Creator in the Return URL field. Subsequently, enter the domain of the Redirect URI in the Domains and Subdomains field.
    
17. Make sure your associated App ID is chosen as the Primary App ID. If this is the first App ID you’ve made that uses Sign In with Apple, then it will probably already be selected.
    
18. Go ahead and click Next and then Continue and Register until this step is completed. The Identifier displayed here is your Services ID.
    
    

Generate a key

19. Next, we'll be registering a new key. Back in the main Certificates, Identifiers & Profiles screen, choose Keys from the side navigation. Click the blue plus icon next to Keys.
    
    
20. In the Register a New Key page, give your key a name.
     
    Check the Sign in with Apple option and click the Configure button adjacent to it.
    
    
21. In the Configure Key tab, select your primary App ID. Then click Save.
    
    
    
22. Apple will generate a new private key for you and let you download it only once. Please download and safely store the .p8 file. Also note that the Key ID displayed here will be required later. Click Done.