How do your integrate paypal payment to the suggested donation amount and "other" amount

Please show us on how to do the calculate amount  with suggested donation and "other" amount to be input by our customer

You can refer to this guide to see how to do this: https://www.jotform.com/help/275-How-to-pass-a-calculation-to-a-payment-field. You would need to add a calculation widget in your form and use it to pass its value to the payment gateway.

I've created this cloned version of your form: http://form.jotformpro.com/form/51247728598974 so you can see how it works. Feel free to clone the form to your account if you want to inspect it further.