Today, I'm going to install the latest Apache2 and PHP7 on an Ubuntu 18.04 server and enable the HTTP/2 protocol. To upgrade an existing Apache system to use HTTP/2, follow these simple instructions:
$ sudo -i
$ apt-get install python-software-properties
$ add-apt-repository -y ppa:ondrej/apache2
$ apt-key update
$ apt-get update
The above commands add the latest apache2 repository to your system and updates the list of available packages your system is aware of.
$ apt-get upgrade
Now your system is up to date with the latest packages. I am assuming you already have Apache/php etc running. Now we can enable the module in Apache:
a2enmod http2
Now we have to edit the virtual host and add this protocol to it.
<VirtualHost *:443>
# prefer http over http1
Protocols h2 http/1.1
.....
</VirtualHost>
Now restart Apache and you should be good to go !