I studied many links about bitcoin trxs and about generating scriptSig. Finally I couldn't understand how to make this part.
for example I read this links:
What is relation between scriptSig and scriptPubKey?
How do you create a scriptsig for a new raw tx?
How to create the <sig> <PubK> part in "scriptSig"?
I found that I must sign a thing but whats that thing ?
exactly and step by step What should I put together and then sign it?
specially if I had more than 1 input how make sigscript ?
I have a library that does the sign operation for me. however, I don't know what structure I need to use for the message that is going to be signed especially when there are multiple outputs.