Chosen Solution
so I spilt some nail dehydrator and it flooded into just my space bar but thankfully it dries super quickly like acetone basically. But now only the rightish upper side of my keyboard lights up. How is this solved and should I fix this? Or would this be too difficult to do? Also I have done a SMC reset and nothing was fixed.
The keyboard backlight is a simple assembly of three sheets where there are 6 leds projecting light. Leds can’t be replaced but backlight sheet can be easily found for sale online and it comes pretty cheap. Replacing that can be a bit challenging instead, as to access it you have to remove all and everything from the topcase, logic board, I/O board, battery and speakers too, but it can be surely done, depending on your care and patience. Here you can find all the guides you need to get an idea of what needs to be done. MacBook Air 13" Early 2015 Repair
At this point I think you’ll need to live with it. Otherwise you’ll need a new keyboard which is a big job.
I would be more concerned about killing your keyboard at a physical level over killing half the backlight. The backlight isn’t essential and you can live without it, but if the keyboard dies you’ll need a palmrest (keyboard is riveted in on this model) to fix it. See how your keyboard lasts for at least the month from when you did it. If it continues to work, live with the damage and consider yourself lucky. If it gets worse, you need a keyboard or palmrest. The stuff they put in nail primer isn’t much better then acetone in the amount of raw damage done.
