Can I use automatic revalidation when H4 extension application pending?

My H4 visa , I 94 both are valid till Feb’22 but my visa stamping on my passport is expired. My Husband’s H1B is approved till 2025. I have a H4 extension application pending. Can I visit Mexico and get I 94 extended using automatic revalidation? If yes what will happen to my pending H4/ H4 EAD application? If no, what are my other options?

Yes. You may need Mexico tourist card if your H1B visa has not expired.

They will keep processing.