How to create a form with PayPal and check payment option?

I would like the option to pay by PayPal or check - I used the conditions you provided in another thread to set that up, but I want to make sure they cart is still submitted when paying by check. 

You can create a new set of products that will show (created with regular checkbox fields) and then show those products if check option is selected:

And then use conditions to show/hide that field based on the payment method chosen:

You can create a similar condition for PayPal field.

Please check my clone of your form: https://form.jotform.com/70415014659958

Let us know how it works for you.

Thank you!