Apologies for the delayed response. Basically, when I add the above-mentioned code I get the 500 error. I tried with removing the hooks as well but the same result.
THE ACF fields show up in the backend.
Just to give you some context, I am trying to add the repeater field on a page like this https://faded-print.flywheelsites.com/platform/.
I am assuming that this page is a PAGE and the backend file is page.php
Could you please confirm that the very 1st step is to create ACF fields in the plugin area and then proceed to add the code?
Cheers
Ally