Hi There, could someOne guide me on how to make custom tool for my viewport

Hi There,

Could some1 guide me or direct me on how to make custom tool for my viewport and NOT from blueprint or widget, because they require me to play the game first, and it’s heavy

.I included the pic as well.

I’d like to create a button on my viewport to toggle,for example, bloom or depth of field on and off.I know I can click show >Post Processing> then bloom but then that;s like 3 steps.I;'d like to create my own custom viewport tool so everytime I launch my unreal it will just be there by default

Thanks so Much!!