from someone who has a 2010 MacBook air:
repairing your MacBook pro might not be the right direction.
when the keyboard starts acting up without any reason like being dropped or crumbs under the keys
is an indication of the MacBook pro need more attention and funds down the road.
After time these laptops are not worth the investment of repair, especially potentially wasting $500
which by the way is too pricy and there has to be some other source.
from mid 2018 to late 2019 that MacBook air would not type all the letters.
luckily there was a great $20 bluetooth keyboard the solved this problem.
kinda sucked toting that outside on a nice day to type some content, but that did the trick.