Submitting A16z Application Without a Working Product/app

I am building an ambient and passive mental health measurement application. I do not have a working prototype yet and I am new to this space. I have spoken to a lot of clinicians and users to understand the problem, identify core requirements, and only recently started building it after realising there is a strong need and want for the tool. However, I am yet to have a working prototype. Should I submit an application to accelerators like A16Z speedrun? And if so, what all should I submit? What all should I put in the pitch deck? Should I make a pitch deck at all at this stage?