How to submit i539 for H4 extension, i don't have H1B extension USCIS receipt yet?

[Aasma]

For i-539 you need to provide the USCIS receipt number for the extension or change already granted to your spouse." We haven't received the receipt number yet for my husband's filed extension and it might be at least a week before we get it. Can i submit it now and then provide the receipt number later when we receive it? I cannot wait for a week as my i-94 is expiring on 19th May 2021

[rkk09]

Hi,
In this case, you should have filed H4 Ext along with H1B Ext petition together... Its not really possible to include or update form whenever we need... We can provide any evidence upon request at the time of RFE issuance.
Thanks