Bad Request on OIDC Authorization Code Flow (step1)

API
2
  1. Don’t use file_get_contents use cURL. Just get cURL installed file_get_contents just is not save
  2. Whats the body response? (Not just the HTTP Code)
  3. It should be a ‘POST’ Not a ‘GET’
  4. see if anything relevant from this duplicate post OIDC Authorization - Bad Request - PHP