This endpoint requires the 'pages_read_engagement' permission or the 'Page Public Content Access' feature

I am trying to get posts (public data) from a page where one of the app testers is an admin, the app is still in development, as we read in the docs that Page Public Content Access is available for pages where The person who holds the admin role for the Page also holds an admin, developer, or tester role on the app

https://developers.facebook.com/docs/apps/features-reference#page-public-content-access

curl -i -X GET \
 "https://graph.facebook.com/v8.0/{page_id}/posts?access_token={app_id|app_secret}"

receives

{
  "error": {
    "message": "(#10) This endpoint requires the 'pages_read_engagement' permission or the 'Page Public Content Access' feature. Refer to https://developers.facebook.com/docs/apps/review/login-permissions#manage-pages and https://developers.facebook.com/docs/apps/review/feature#reference-PAGES_ACCESS for details.",
    "type": "OAuthException",
    "code": 10,
    "fbtrace_id": "xxxxxxxxxx"
  }
}

What are we missing? does it makes a difference if the tester(who is the admin of the page) is the one who generates the app token (app_secret)? or it is the same regardless?