I’m premium account, how to set up other 4 device to use??
To set up your other devices to use VyprVPN you would first want to install our application on your devices. You can locate download links here: https://support.goldenfrog.website/hc/en-us/articles/204545503-VyprVPN-Desktop-and-Mobile-Apps
Once installed you can login with your username and password on these devices and begin using the VPN.
I can not find multi-device button in the app of setting icon.
How do I enable multi-device?
To enable multi-device, tap Settings icon, then tap multi-device. Once you select “Enable,” you will be able choose your data retention time limit for storing messages on the server. Here is where you can set a passphrase to access your Cyphr account on your other devices.
The “multi-device” feature you mentioned there is for the Cyphr application and not a function on the VyprVPN application. For clarification can I ask are you trying to use Cyphr across multiple devices or VyprVPN?
If you’re using VyprVPN the steps I provided previously would be the ones to take.