Have you tried Google, seems the new reset is:
"How to force reset your iPhone 8
1) Press and quickly release the Volume Up button.
2) Then press and quickly release the Volume Down button.
3) Finally, press and hold the Side button until your see the Apple logo. Note you should not release when the screen goes black. Instead, keep holding until you see the Apple logo on your screen, at which point, you can safely release the button."