I want to use the App Store Server API. so need to generate the JWT. the document is: https://developer.apple.com/documentation/appstoreserverapi/generating_tokens_for_api_requests
To get your issuer ID, log in to App Store Connect, then:
1. Select Users and Access, then select the Keys tab.
2. The issuer ID appears near the top of the page. To copy the issuer ID, click Copy next to the ID.
in the step 2, I can't find the issuer ID on the top of the page.
do you have the same issue?
The Issuer ID is indeed at the top of the page of https://appstoreconnect.apple.com/access/api (the place you get to once you login, select 'Users and Access' and then 'Keys'), but only after you've created your first App Store Connect API Key.
I went through the process of creating an IAP Key, following the Apple instructions, but obviously missed any reference to creating an API Key first.
In short - create an API Key on the 'App Store Connect API' selection, your issuer ID will appear near the top of that page.
I faced same problem, but got issuer id after generating key for appstore connect api.