1 Gal... Well, almost

Brewed a 1 gal kit… fast forward to bottling day. I only managed to get 8 bottles.
I realize this is due to boiling off too much water…

For next time:

Obviously i could boil lower so less water loss.

Could i also add water to the fermenter and Wort?
I’m assuming i would need to either boil the water and cool it, or use distilled water.

can anyone help with this?

Purposely brew it strong, then add some boiled distilled water at bottling time. You need to boil the water just to remove the oxygen and prevent stale beer. Then you’ll get your full 12 bottles or whatever you wanted. Or… you can buy a bigger fermenter and start brewing 1/3 or 1/2 size batches (compared to the standard 5 gallon kits), or as much as you want.