How?
I can't takeoff because there's no GPS. I can't figure a way to disable the GPS requirement.

Hi!
You might be better off posting your question in the 'products' section of this forum.
That is way more active.
Just create a new thread here : https://forum.dji.com/forum-129-1.html and select the right category / subcategory.

Hello there Wgander. Good day and thank you for reaching out. Please be careful while flying indoors as the DJI Spark stabilization feature may experience interference and might affect the said DJI drone. If you really need to fly indoors kindly please use a DJI Spark Propeller Guard. The DJI Spark Propeller Guard protects the propellers and other objects from damage. Just a reminder that when the said drone's GPS is weak, the vision system is activated automatically when the drone is turns on. No further action is required. The vision system can be used in indoor environment where GPS is unavailable. Using the Vision System, the drone can hover precisely, even without GPS. Thank you.

You haven't answered my question. I do use prop guards. The problem is that my Spark won't take off. It displays there is no GPS signal and won't allow me to take off. There must be something in the menu that I can change to allow flight without GPS, but I don't know what to do.