How to integrate Signature pad in a web application

I want to integrate a signature pad in my web application (.net or java). I have a form and my idea is to capture the signature and display it as soon as it is typed on the pad, and upon a submit sign a pdf(not a concern).

My general questions are how do i capture the signature from the pad, is there a general way for all vendors or do i need to use vendor specific sdk-s, i read this thread https://stackoverflow.com/a/50208561/7905703 that says there are local applications and that i need to call the local application and get the signature but i couldn't find more info about the way this works, are all vendors supported by these application etc.

I haven't bought a pad yet first i wanted to do some research from integration standpoint before i buy a pad from one of the available vendors(topez, wacom, or else).

Thank you :)