Deactivating HTTP/2 support
That option allows you to disable HTTP/2 support on the web browser that runs your test. As a consequence, all the HTTP transactions that should have used this protocol will use HTTP/1.1 instead.
Thanks to this feature, you will be able to compare your website performance through a web browser supporting HTTP/2 against another browser that doesn't.
Disabling HTTP/2 support for a web page that doesn't load any HTTP/2 requests won't have any impact (our option does not let you simulate your website performance if it was using HTTP/2).