Battery swelling = battery replacement. I suggest you replace the battery. Don't wait, as swollen batteries can explode. Apple will charge $200 to replace, or try a local authorized dealer. You can try install the battery yourself by ordering from iFixit.
If I were you, I would just get a refurbished M1 MacBook Air from Apple, instead of spending $200 on the battery.
If I were you, I would just get a refurbished M1 MacBook Air from Apple, instead of spending $200 on the battery.