Solved
How to add a back button to a specific block.
How do you add a back button to a specific block?
Best answer by TomG
Turn on the back button for the survey and hide it using JavaScript everywhere you don’t want it.
I would put a single script in the header that uses an embedded variable to specify if the back button should be shown or not.
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I also tried to hide ALL buttons, and it works (as in, the NextButton is not visible in the first page):