How to issue a Let's Encrypt certificate (on nginx)?

Question

Nginx

An error occurs when obtaining a certificate:

Waiting for verification...
Challenge failed for domain launch.example.ru
http-01 challenge for launch.example.ru
Cleaning up challenges
Some challenges have failed.

IMPORTANT NOTES:
 - The following errors were reported by the server:

   Domain: launch.example.ru
   Type:   connection
   Detail: Fetching
   http://launch.example.ru/.well-known/acme-challenge/1Xq3iphwFCC-mXzGOx8zVH989dE-qdNrcG07Ztt_-wg:
   Server is speaking HTTP/2 over HTTP

   To fix these errors, please make sure that your domain name was
   entered correctly and the DNS A/AAAA record(s) for that domain
   contain(s) the right IP address. Additionally, please check that
   your computer has a publicly routable IP address and that no
   firewalls are preventing the server from communicating with the
   client. If you're using the webroot plugin, you should also verify
   that you are serving files from the webroot path you provided.

ps The real domain is replaced by example.ru

Answer 1

You didn't show the config, but I'll be a telepath: I listen 80 http2;did that, didn't I?

Answer 2

Remove from the HTTP section listen http2, add a location /.well-knownleading to the directory where LE will put the verification files.