If you are using a android device please download the apk from this link
https://321inter.net/downloads/app-release-VPNClient.apk
make sure your device is allowed to install from unknown sources
once installed
then enter your username and password.
you can find your username and password but loging into the betvhosting.net, click on services
https://betvhosting.net/clientarea.php?action=services
then click on the your newest active product, scroll down , you will see vpn server information and your own details.