Hi
The requirements for setting up Apple Pay on iPhone and Apple Watch are detailed here:
Set up Apple Pay on your iPhone, iPad, or Apple Watch - Apple Support
Those requirements include having a supported bank or store card in a country where Apple Pay is currently available:
Apple Pay participating banks and store cards - Apple Support
If you are located in one of those countries, check the following:
- Your region is set to the correct country: Settings > General > Language & Region > Region - set to your country.
- You have Touch ID or a passcode set up: Settings > General > Touch ID & Passcode.
- You are signed in to iCloud with your Apple ID: Settings > iCloud.