I use applications generated by insurance companies which they secure with a password but they allow us and clients to sign electronically. The basic How To says to send for signature I need to "Prepare Form", complete fields, then send for signature. Adobe will not let me Prepare Form due to security settings. How do I sign if I cannot "Prepare Form" then send for signature?
Those instructions are how to create a form... If the file you have already contains form fields then you can interact with them directly. You don't need to use the Prepare Form command.