When you logon to Fritz!Box, go to top right of UI and there should be three dots, click that and an option to change view from Standard View to Advanced View should be presented (slide bar).
But as yours is ISP supplied, this maybe changed from stock build 
To factory reset, On the left-hand menu, click System, then on Backup. Click the Factory Settings tab. Click on Load Factory Settings. You will then be prompted to confirm you wish to factory reset the router (or very similar to this).
In a completely sane world, madness is the only freedom (J.G.Ballard).
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