PTF not working with Approval Workflow; adding next approver step

PTF--Hi.  I am trying to create a script that will work with Approval Workflow for vouchers.  (Note: all our vouchers that are in voucher approval, and not pre-approved, will have an 'initial approver'.  We then have the 'inital approver' add the 'next approver', if they don't have the $$$ authority to approve the voucher themselves.)

Steps running successfully in script so far:

open web page and sign in

navigate to Accounts Payable >  Vouchers > Approve > Approval Framework - Vouchers

insert voucher id and open page

close a 'related content' box that appears at bottom of page

click the + sign in the 'Voucher Approvals' section of page