The keyboard is probably short-lived anyway, so a replacement is a good idea. Just take photos of every phase of disassembly and keep the parts and screws arranged on trays or something.
A repair is theoretically possible with silver paint applied to the damaged conductive paths in the switching film, https://lemmy.world/comment/14076165 , but all the other switches will remain old and unreliable.
You might check what AliExpress has to offer. My Lenovo Ideapad 530S's film-switched keyboard started malfunctioning at three years age. I replaced it even though it was melt-studded (?) in - plastic rods poke through the keyboard, their ends melted flat and wide. Some instruction video told me to cut the stud ends off with a chisel, but I used a mini drill. The most difficult part was to hold the keyboard pressed in its place with weights on sticks while doing a temporary re-melt of the insufficient rod ends with a soldering iron (I could have skipped that). After that, I covered the re-melted ends with epoxy for near-original strength. The repair was successful.