Search Metal Brake, they are very easy to make. Don't require very much in the way of materials.
Can be made portable, using "C" clamp mount to work bench.
Rigidity, determines the sharpness of the bend, & sheet metal thickness to be bent.
If sharp bends are not a big deal, you could even make one using heavy wood
Betting some will post some home builds for this ...I know they are out there..