Once connected to your Directadmin console :
Click on Select PHP version
There you can :
(1),Choose your PHP Verions
(2), Validate the change
(3), Save the Change
(4), Check the PHP Version currently active for your account.
We recommend that you check that all your website component are functional after PHP Version change.
We recommend not to use the latest PHP Version and also not to use the 4.X and 5.X version as they are deprecated.