1. Log into your Developer Account.
2. Select Certificates, Identifiers & Profiles.
3. Select Certificates and create a new certificate.
4. On Software, select Apple Distribution and then Continue.
5. Go to your app builder and save the highlighted link as .certSigningRequest.
6. Select the file generated on the last step and upload it. Then, continue.
7. Download the certificate and go back to the Certificates Menu.
8. Go to your app Builder and upload the certificate from the last step.
9. Go back to the developer account, and go to Identifier's menu. Then create a new identifier.
10. Select Apps IDs and then click continue.
11. Select App and continue.
12. Select a description for your identifier, and fill the Bundle ID field with the ID from your app builder.
13. On the same page, under Capabilities, select Push Notifications and Sign in with Apple. Then click continue
14. Click register and go back to the certificates menu.
15. Go to Profiles menu and create a new Profile.
16. Select App Store under Distribution, then click continue.
17. Select the App id created on this article and click continue.
18. Select the certificate you created earlier and then click continue.
19. Chose a name for your provisioning profile and click Generate.
20. Download the Provisioning Profile file, and upload it to your App Builder.
21. Go to your Firebase account console on https://firebase.google.com/ and create a new IOS app.
22. Copy your Bundle Id from the app builder and paste it into the App Bundle ID field, chose a name for the app, and click Register App. After that, click the X button to go to your console dashboard.
23. Selected the created app, and click on the configuration button by its side.
24. Scroll down on the page, and download the GoogleService-info.plist
25. Upload the file from the last step to your app builder.
26. Go to your API console from the Google Cloud platform. Select your project and go to Enabled APIs & Services. Select the ENABLE APIS AND SERVICES button.
27. Select Maps SDK for IOS and enable it. After that, go back to your APIS and Services console dashboard, and go to the Credentials area.
28. Create a new API key.
29. Copy the generated Hash, and paste it into your app builder.
30. Select the newly generated key, and edit it.
31. Change the Key name. On application restrictions, select IOS Apps. Add your Bundle ID to the request. On the API restrictions, select the Don't restrict key. And then Save.
32. Before building the app, make sure to create your app on App Store Connect. Log into your app store account and select My apps.
33. Create a new app.
34. Select IOS, your app name, and the primary language, select your Bundle id, and on SKU, paste your bundle ID from the app builder. Then click create 
35. You need to enable Apple Login to be able to build the app. Follow this article so you can enable it.
36. After creating the app on App Store Connect, you can build your app. If you have invited [email protected] as a developer to your account. The build will automatically be sent to App Store.