I am using the console. I'm getting this error on the first stage (Configure application). I have tried to create an appengine application on multiple GCP accounts but I'm getting the same error "error while initializing app engine".
I have tried using different GCP accounts. I have tried adding my card details.
I observed the same problem on April 14, having tried many times with different locations.
What worked was using the gcloud
CLI tool on a local machine (you could also try online with "Activate Cloud Shell"):
gcloud auth login
gcloud config set project <project>
gcloud app create