If you want to create a multistep form and show only Payment Methods on last step, you can follow this trick to show the form.
Step 1 ) Create Multipstep form with 2 or 3 steps
Step 2) On 3rd Step, Add a new section
Step 3) Named it “Hidden Section” also add a “class”- wfacp_hidden_section in CSS Class section
Step 4) Create a new field – Hidden Field with any Label and any Field ID
Step 5) Drag that hidden field to your checkout form step 3
Step 6) Add this CSS snippet to your Global CSS
Here is your final output with the Payment Method on last step