How to pin sites (Nightly)?

On this tablet I’m using Nightly (because addons). I’m trying to set up the Top Sites as I did on Fennec. Some time ago I pinned two sites - the first two on this screenshot (the pins are very faint) but I’ve forgotten how I did that.

How do (did) I pin sites?

The sites, as you can see, are barely readable but I can’t find a better way to select my favourite sites - equivalent to the bookmarks toolbar on desktop.

Open the website you want to pin, open the menu (⋮) and select “Add to top sites”.

On Fennec I do it from bookmarks.The disadvantage of starting from an open page is that many sites will redirect. So if I type in ‘’ the page I get - which might depend on my cookies, location, device…, might be<some_long_string>&foo=something etc
Is there a way of editing these Top Sites to get rid of that?
Or finding out what URL a top site goes to before clicking it? (In Fennec I can copy the address.)