H4 EAD - Correct receipt# of H1B spouse to use

I’m applying H4 EAD for wife separately myself.
My company has filed my H1B and H4 extensions separately.

Q29 in Form I-765 is asking for H1B spouse receipt#. But, I’ve not yet received the receipt# of my H1B extension.

Please confirm if I need to wait for H1B receipt# before filing H4 EAD application?