We need photos of the damage, but knowing these it sounds like the LCD assembly broke rather then the palmrest. Very common with these due to the brittle plastic contracting and expanding.
Since there is no good way to glue the brass back in once it happens, you’ll need to replace the back LCD cover of the machine, which we need to model number of to check what the HP Spare# is. There are a few of these it’s only sold as an assembly (primarily the glass cover variant) but the ones with a normal LCD bezel tend to be available with the part available piecemeal and everything else can be reused.
If it’s an assembly only part, you’ll need to buy a good used one and transplant everything to the used part.