The easiest way to use IPVanish on iPhone or iPad is through the App Store app . Search "IPVanish" in the App Store.
If you are seeing "API errors" or using a custom script, consider these troubleshooting steps from IPVanish Support :
💡 Use the Fastest Available server setting to let the IPVanish API automatically select the best endpoint for your current network. How to Use IPVanish (iOS)