I did a quick test on your checkout and I can see you are still on the v1 plugin, see below:
Please see below an example:
On the below example go to Setting then Payments (On your backend/admin page)then please Uninstall/Deactivate Peach Payments at the arrow under Payment providers(v1) and add us on Supported Payment methods(v2):
Click Add Payment methods as per the above then as per the below you will find us on the 2nd tab Search by provider: