Get a keyboard cleaning kit, like this, which gives you tools to very gently pry a key upwards so you can clean under it with one of the brushes (or the specialty Q tips, see below): https://www.amazon.com/gp/product/B08QV9T1HN/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

And also I have an alcohol-free lens cleaner spray that I use to clean my screen & keyboard--spray a little on a microfiber cloth and gently wipe with that (or put a little on a specialty Q-tip). I can't find the exact one I use, but this seems to be similar, from the same company: (Bonus, use it to clean your glasses, it's great) https://www.amazon.com/C-Clear-21-Cleaning-Cleaner-Solution/dp/B00BC6GEMO?ref_=ast_sto_dp .

Lastly, I got these to help w/ makeup but they're also great for cleaning a keyboard, much less "lint" than a regular Q-tip; https://www.amazon.com/Precision-Cotton-Double-Pointed-Makeup/dp/B07Q4RW17G/ref=sr_1_2_sspa

I am NOT an expert but if your laptop is still working fine it sounds like you just have to very very carefully clean the residue of the sticky jam off the underside of some of the keys. Do not use water.

Edit: the microfiber cloths I use: https://www.amazon.com/gp/product/B008FPTID2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1