On Android, the Wi-Fi settings take a manual proxy: touch and hold the network, choose modify and fill the host with the address, the port with 20001 and the username and password from the order.
When the device refuses
Apps with their own connection ignore the Wi-Fi setting. In those cases, use an app that accepts SOCKS5 proxies on port 20481, or a separate VPN profile.
After setting it up, open /meu-ip in the device browser: what shows must be the purchased address.