Thank you for the response Niyas Raphy. But I dont want to create a seperate code for it, I wanted to use default xmlrpc APIs and test it on postman. Let me know if there is a way for it.

you dont need to add extra code for it.
call the existing create method and pass value into it

I need an example for it. Couldn't find it. URL, Reqeust Body etc

It seems you haven't gone through the above odoo doc, url will be the url of odoo instance.
please read above documentation and try it out

I think the question is very specific API to generate leads. Giving a link to Odoo's documentation, great answer.