Is there a way to disable HTTP/2 on a Phoenix app running on Fly?

Phoenix
1

I’m attempting to run some tests on my deployment and I know that it’s possible to disable HTTP/2 when using Nginx. But, for a Phoenix app running on Fly.io is there a way to disable HTTP/2?

I’ve tried changing the following settings in my toml.

[http_service]
  ...
  [http_service.tls_options]
    alpn = ["http/1.1"]
  [http_service.http_options]
    h2_backend = false

[services]
  [services.ports]
    handlers = ["tls", "http"]
    port = 443
    [services.ports.tls_options]
      alpn = ["http/1.1"]
      versions = ["TLSv1.2", "TLSv1.3"]
    [services.ports.http_options]
      h2_backend = false