I'm trying to make a support beam and for the life of me I cant figure out how to produce this one corner of a part I've modelled.

I have tried the surface fill feature but it looks like you cant adjust the thickness of the fill. I need to maintain the material thickness across the whole extrusion.

Any help is appreciated!

Edu  ​​​​​​​SOLIDWORKS ​​​​​​​3D Modeling ​​​​​​​