Hey Ofi Khan,
We do all of your steps and do everything right, only thing left after creating facebook key and secret, is to click on the generate instagram token right? something like that?
well, when we get to that point to generate the token, nothing happens, or if it pops up, nothing loads, or says error. that is.. when sp page builder version 4.0.6+ is installed..
when we install sp page builder version 4.0.5, the instagram token pops up and gets generated, however, when we click save and close, it does nothing.
at that point, at least we have a token, we copy that token, and manually insert it into the database via phpmyadmin, then the instagram gallery finally works after that much work.
on top of that, the instagram token get broken from time to time randomly, so we need to go in painstakingly again to get it all setup again with the process above.
if you want access to the website that has this issue, so you can see, i am willing to let you in to take a look, just let me know, and i'll put it in the hidden content. thank you for your question, Ofi Khan!