Can I fill DS160 based on H4 - i539 Receipt Notice - H1-B i129 petition is in approved state

Hi All,
Below is my case
My H1-B (Case Type – i-129 Petition for Non-Immigrant Worker) is approved and is valid till July 2023.
My wife’s H4 (Case Type - i539 Application to Extend/Change Non Immigrant Status) is in process from last 6 months, and all we have is the receipt notice from USCIS. Also we are still awaiting bio-metrics appointment for my wife.
I am planning to travel to India in July 2021, so that I can use drop box for visa stamping. I will not be eligible for drop box in Aug 2021, so want to get the stamping done before that.


As my H1-B is already approved, so I can fill my DS160 without any issues and schedule an appointment in July 2021, but I wanted to know - if I can fill DS160 for visa stamping for my wife’s H4 visa based on Receipt Notice. Assuming my wife’s H4 will be approved by then, so we can go together and use the drop box for both of us at one go

Also wanted to know, If I fill DS160 in next few days and pay the visa processing fee, then during the appointment scheduling, will I be able to pick a date in July 2021, or scheduling 5 months in advance is not possible