Making a Button Active After Scrolling Through Text

I’m working on a sign-up form where I’d like the user to have to scroll through text, and then have a button become active only once the bottom has been reached.

Alternatively, I’d be okay putting a button at the bottom of the element below the text, so it is either all in a modal or in a box with inner-scroll, where the main “continue” action isn’t available until the button is pressed.

I can’t seem to figure out a way to tackle either approach.


Did you ever figure out a solution?