What is HTTP v2?
HTTP/2 is a newer version of the HTTP v2 protocol, which, compared to HTTP v1, allows much faster processing of user requests and increases the speed of the site. HTTP/2 requires HTTPS connection support. To make the site work over HTTPS, when creating or changing a WWW domain, first enable the Secure connection (SSL) option and configure its settings. Enabling support is available only if ISPmanager is installed on a server running CentOS 7, Debian 9, Debian 10, Debian 11, Ubuntu 18, Ubuntu 20 operating systems. Nginx 1.12 (or higher) web server and OpenSSL 1.0.2k (or higher).
How to enable HTTP2 in ISPmanager server control panel?
To enable HTTP/2 support in ISPmanager, go to Settings → Web server settings → Main settings (Global settings).
In the window that opens, activate the option "Enable HTTP/2."
After that, after some time, usually within a few minutes, HTTP / 2 will be enabled for all WWW domains that have the Secure connection (SSL) option active in the domain properties.