回複：Please help my case!!! Thxxxxxxxxxx

If you will use EAD to work for new company, the only document that you need to provide your new company is EAD copy. Some people like to send AC-21 letter to USCIS (this is optional) to approve their new job is still in same or similar category. This is usually when they transfer their H1B.

Since your I-485 is still pending, to be safe, you will want to keep your job with same or similar responsibilities and if possible, keep same title. This is just in case they send you REF.