Roof sheet around the foundation? Will this work?

[Klonkers]

I am going to install window sections flush with the edge of a concrete slab and have never done it before

I understand that one should have some kind of flashing under the actual track.
One idea was to put fascia boards around the entire slab to tidy up the edge and help make it a bit more watertight.

The image below - do you think it would work well?

The flashing I am considering using is: https://norosteel.se/sv/platbeslag/ovriga-platbeslag/vindskiva-offertforfragan.html

Or should I choose another type of metal or no metal at all?