H1B extension is under processes and yet to receive receipt and H4 i94 about to expire, yet to file H4 extn

My H1B extension is filed a week back in premium and waiting for the application receipt to file H4 extension submission and the H4 I94 about to expire in 10 days, if I fail to submit to file before i94 expiry, Can I submit H4 extension after i94 expiry once I receive the receipt?

Could you please advise?

You should file H4 for extension before i94 expiry.