Hello sarahcakes87, thank you for reaching out and welcome to the Samsung Community. I understand you forgot your Samsung Pay pin and you would like to reset it. Forgetting your Pin requires resetting your Samsung Pay account. To reset the app, navigate to your phone's Settings. Swipe to and tap Apps, and then select Samsung Pay. Tap Force stop, and then tap Storage. Tap Clear cache, and then tap Clear data. Once these steps are completed, reopen the app, and follow the on-screen prompts. During the setup, you will need to create a new PIN and add your credit cards again. For more information please review this link: https://www.samsung.com/us/support/answer/ANS00078424/#:~:text=Change%20your%20Samsung%20Pay%20PIN%2... 2Dscreen%20instructions.
Depends if you gave the option to reset it using your samsung account you can do it that way otherwise you can try using find my phone and see if you have the option to unlock the phone that will reset most locks not sure if it will do what your asking but those are my only suggestions
