Apple Pay not working on my device

That’s a pretty vague issue statement not giving anyone who wants to help much to work with.

Was it working previously and then quit ?

Are you trying to use it for the 1st time ?

What indications are you receiving ?

What does not working mean? Please provide examples of how it doesn’t work. It will also be helpful if you provide details on what device you’re using and what iOS your device is using. Have you done any troubleshooting and if so specifically what did you try?