Hey @John C.136, thanks for your feedback on this!
While this is not an option at this time, maybe you could use the Markup option in Dropbox Capture as a walk-around?
From there, you'd be able to add shapes, arrows, or text as well as draw on your screenshot too.
You can find more information about this here.
I hope this helps to some extent and please let us know if you have anything else to add or ask.
Thanks so much, John!