EAD when I94 is expired and H4 extension in progress

My employer applied H-1B and H4 visa extension for my wife. My H-1B visa got approved but my wife’s H4 petition is still pending with USCIS.

I have below questions:

As her I94 is already expired, Is it ok to mention expired I94 number in form I765 (in section 21.a) . Please suggest/help. OR should we leave that field blank. Do you recommend to wait for H4 approval first and then apply for EAD ?

You can provide the H4 receipt # instead.