Low/no code signup/demo page for startup?

I have a few startup ideas that I just want to quickly create a Figma/smoke and mirrors demo video for. Slap that demo video onto the website with a sign up button and gauge the interest. Maybe something like a Jekyll page which stores the signup data into google forms?

Ideas that I can directly identify and approach potential customers I am doing so.

I am a fullstack developer and could obviously code this with react/flask/whatever etc... but what is the lowest code/no code solution so I can focus on moving fast rather than coding?