Some Feedback on the site:
"Free demo" makes you register and the description makes it sound like you have to link your account to Stripe right aways. This is quite misleading, imo. "Demo" in my mind doesn't even include registration, it should be a demo of how the service would operate.
"Sample Menu" is something that looks like a demo, but it is quite worthless, because it's not a bit interactive. You can't even add menu items to the basket.
If I was a restaurant owner I wouldn't be very impressed by the "Sample Menu" and I would be very reluctant to register because a "Free demo" doesn't entail signing up for Stripe in my opinion. This sounds more like a trial than a demo.
The registration description was inaccurate, you don't need to sign up for Stripe right away to look around the members area, thanks for pointing that out. Also, I agree with the free demo comment, I'll change the button to "Sign Up".
The add to cart functionality on the sample menu should work, what browser are you using?
If I was a restaurant owner I wouldn't be very impressed by the "Sample Menu" and I would be very reluctant to register because a "Free demo" doesn't entail signing up for Stripe in my opinion. This sounds more like a trial than a demo.