Create a new Apple ID for a region where the 1S VPN app is available.
Go to Apple ID website and create a new account
When creating the account, select a region where 1S VPN is available (e.g., United States). Important: for payment method, select "None" if available
Open the App Store on your device
Tap your profile icon in the top right corner, scroll down and tap "Sign Out"
Sign in with your new Apple ID (your main iCloud account will remain unchanged)
Search for "1S VPN" and download the app
Go to Settings > [your name] > Media & Purchases > View Account
Tap on "Country/Region"
Select "Change Country or Region" and choose a region where 1S VPN is available (e.g., United States)
Follow the on-screen instructions. The system may ask for a payment method for the new region (select "None" if available)
After completing the region change, open the App Store
Search for "1S VPN" and download the app