At Versio you have the possibility to enable certain modules, for example 'imap', 'mysql' or 'opcache'.
In order to activate these modules you must first select a PHP version. In article 'How do I select a different PHP version?' You can read how to choose a different PHP version.
When you have chosen a PHP version, you will see the following overview where you can activate certain modules.
If you have checked the module you want to use, you can press 'Save'.
You have now activated the module, which is immediately active on the server.