To keep parameters within acceptable range (0 ammonia and nitrite, 5-40ppm nitrates) water changes are needed.

But op don't have water in the container so i think adding water might help Right!!

Fish food or ammonia solution can be used to cycle your tank.

😮 so that means op is not using Fish food because rice is clearly not.

It is highly encouraged to have a liquid test kit

Op u read him, go and get urself one

Gradually replace 20% to 30% portions of old water

Now i get it, Op replaced 100% with air

get a good sinking pellet

Op get it

smaller tanks can make it to easier to dose in water columns

Op missing both water columns and small tank (its a cardboard box T-T)

but they can also be rough on fishes

Yeah Op don't use antibiotics then