Does API quick start remove chlorine from aquarium water?

First off, Yes, I just started my aquarium cycle with fish. Please don’t jump all over me about it because I have learned my lesson. I’ll most likely be taking the fish back to the store if they will take them. I started off with 4 guppies and 2 mollies, and within less than a week 2 guppies have died and all my other fish are at the top gasping for air even though I have added two air stones (it’s a 20 gallon) because I thought it was due to lack of oxygen, but it hasn’t helped. I thought the quick start was a good choice because it was for starting fish aquarium cycles and I was told it was a dechlorinizer by the person working at the store. The staying at the top could be a sign of chlorine poisoning from what I’ve read... I’ve been doing 20 percent water changes daily and treating all the water I put back in with the quick start before I put it in. So does it not work? Is that not what it’s for? The guppies were already doing this at the store before I bought them, but there was no circulation in the tank there so I thought they would be fine once I got them home. The guppies have done it ever since, but the Mollies just started last night... Also idk if this is important, but I have one live dwarf lily plant in my tank, just sprouted about 10 days ago and is already huge. I’d provide pictures but I’m not home at the moment.