Support to Let's Encrypt challenge.

certbot certonly --manual --manual-public-ip-logging-ok --domain example.com

Note that Let’s Encrypt will retain and publish IP addresses associated with ACME validation requests, including requestor IP.

Go to http://example.com/.well-known/acme-challenge and update the challenge and the answer.

Make sure your web server displays the following content at
http://example.com/.well-known/acme-challenge/NmJhODAwYmRmMjdhNzEzMTczOGRjNDFhOGQ0MThmZTgzMDIx before continuing:
Vm1wR1UxTXhXWGxXYkdoV1lUSm9WVmx0ZUhkamJGWlhXWHBTVUZaVk5YVlZSbEYzVTNkdlBRbz0K

Challenge: NmJhODAwYmRmMjdhNzEzMTczOGRjNDFhOGQ0MThmZTgzMDIx

Answer: Vm1wR1UxTXhXWGxXYkdoV1lUSm9WVmx0ZUhkamJGWlhXWHBTVUZaVk5YVlZSbEYzVTNkdlBRbz0K

https://console.cloud.google.com/appengine/settings/certificates

cat /etc/letsencrypt/live/example.com/fullchain.pem

openssl rsa -in /etc/letsencrypt/live/example.com/privkey.pem