Prefilling information before sending

Prefilling information before sending

I am trying to work out how I can complete certain details before sending a form for signing
Basically we have an order form, so we can link company/contact details from the CRM no problem
It comes to services/products that we are provding, that would be different for each customer

Currently the sales team have to email it to themselves as Signer 1 to complete them, then email to Signer 2 (customer)
Is there no way to dd fields that can be completed just before sending?