This does not parse. You mean deb https://packages.sury.org/php/ stretch main Then, when I follow your manual, for debian 9, the vhost for froxlor gives a 404 not found where you want me to set database name etc. So after this: Froxlor doesn't load, even if the folder exists at the location you described. Probably because there's no php fpm config whatsoever at that stage? Anyway, you need to change the order in your how to. Because now I'm pretty much stuck, not knowing where to continue..
Just wanted to let you know that your anti-bot question during registration does not work. I tried to fill in the forum URL, like you ask. I tried what is officially 'the URL': https://forum.froxlor.org/ I tried it without https:// in front, I tried without backslash at the end. None would be taken as valid. Because of this bug I registered using a google account, but I generally never do that, because I hate it when I have to link online ID's everywhere, and be dependent on google, twiitter or facebook to be able to login.