Service appears to have been abandoned!
Nothing works! I tried a 3-day trial with their Smart DNS feature on multiple devices, using both the app's built-in method and manual configuration. However, the DNS test consistently returns several DNS servers instead of just one, and I'm unable to access any of the listed streaming services. The last app update was in March 2021, nearly three years ago. Unfortunately, my email support query went unanswered. Based on this experience, it seems that Cactus VPN is no longer supported - save yourself time by avoiding a trial.