Is work experience letter a mandatory document that needs to be submitted while preparing petition for H1B Visa?

I am currently studying right now and I have been recruited by Company A (from campus) which is filing for my H1B. However, I do not have a work experience letter/ relieving letter from my previous employer. Can my job offer letter and last pay slip be used in place of work experience letter/ relieving letter?

Work experience becomes important if it is in the same field and is being used as an example of resume strength. If Company A didn’t use previous employment information as part of data to hire you, then minimal sharing such as last pay stub is needed

Thank you so much for your response, sir.

Yes the experience is in the same field. And yes they recruited based on my previous work ex only. So do you mean to say last pay slip as a proof would do? Or a relieving letter is still required?