Which adhesive should you use if you want to permanently attach a metal part to the laptop that can no longer be attached with screws?

A two component glue? What is the difference between different types (the color is different and therefore the ingredients)

Power glue from Pattex, it has helped me a lot and holds very well

Every common 2K adhesive is used in your application. Personally, I work a lot with small parts from the 3D printer and various metal sheets and only use the "WELDING SEAM" adhesive from HG POWER GLUE. This berserker is an absolute titan among the 2K adhesives and until today I have never had the case that the adhesive did not hold.

In stress tests, my workpieces were more likely to break than the adhesive gave way. Regardless of whether PVC, silicone, stainless steel or copper, the monster sticks everything.

Maybe this glue is a bit overpowered in your case, but if you want to be on the safe side, a clear recommendation.

Epoxy