ᐅ Remove basement windows and seal with concrete.

Hello,
my wife would like to have our basement window removed and the resulting opening closed. The window is completely below street level.
Our basement was poured with waterproof concrete, coated with bitumen, then the perimeter insulation was applied, and finally the dimpled membrane.

My questions are:
1. What is the best way to close the opening?
2. Should I use formwork and concrete? If so, all at once? What is the best way to seal the top edge, considering concrete shrinkage?
3. Or should I use masonry?

Thank you in advance.

Hi, I just wanted to check again if anyone has any ideas?
Thanks

I always only see bricked-up doors and windows; that seems to be the best solution 🙄

What exactly do you want to say with that?

Remove the window and brick up the opening.
If you can’t do this yourself, hire a construction worker.

Oh man, seriously? Is this the answer? Then why even have a forum where you can seek help from knowledgeable people? According to you, either you already know how to do it, in which case you don’t need a forum, or you don’t know and should just go straight to a professional company.
Thanks again.