You noticed that the submit button is disabled in the last step of your iOS publishing process on the CMS side, even though all the required fields are populated with a value. This article explains why this occurs and how you can fix your app-specific password to resolve the issue.
You cannot click on the Submit button in the last step of publishing your iOS app, although you have filled in all the fields. The Submit button appears inactive/deactivated.
This is because one of the fields is not accurate. The most common cause is that the app-specific password does not comply with the requirements, as it has to be 16 characters long.
Check if you have entered the correct app-specific password. Just note it is not the same password as the one you are using for your Apple Developer Account.
If you are not sure what your app-specific password is, follow the steps outlined in the Using your App-Specific Password KB article to check the existing one(s) or generate a new one.
The submit button will be enabled and you will be able to publish your iOS app.