iPhone 17 Pro Max side button not opening Apple Pay

What iOS version are you using? What happens when you double click the side button (power button)? Have you tried double clicking the side button faster and/or slower? Have you done a forced restart?

Force restart iPhone - Apple Support

Since you won’t assist us in helping you, your best opportunity to resolve the issue is with Apple Support.

If you’re in the US, please call  1-800-MY-APPLE, or outside the US, consult the support articles below. In Canada, call 1-800-263-3394.

Contact Apple for support and service - Apple Support

Genius Bar Reservation and Apple Support Options - Apple

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And what iOS version would that be? What about the other questions I asked?