I have been trying to see if anywhere in USCIS notice it asks us to send a copy of work permit, however, have not found a place where it says so.

is it optional or needed ? It would be helpful know what are the
"must have documents" vs what are the "optional (good to have)" documents

If needed, it would be helpful to know where in uscis notice it says that we need a copy of work permit.

can anyone clarify if the copy of work permit is needed.

Thank you for your help.