Bronze Corydora female is panting

[HoneyFish]

You need an ammonia test kit ASAP. Ammonia is highly toxic to fish and, if built up enough, can kill them in less than a day if not taken care of. Also, the test strips are highly inaccurate. I and many others ask you to please invest in an API Master test kit, linked below. Your fish will thank you.
*edited to fix a typo
https://www.amazon.com/dp/B000255NCI/?tag=ff0d01-20

I just tested the water with my ammonia tester kit, and everything came back fine. Still unsure what is causing her to be stressed, but I would like to thank you again for telling me to get the ammonia tester. It's nice to know if my water is safe for them or not and it's already brought me peace of mind.