Ok, so I checked the roots, it isn't circling the pot, it has lighter roots holding the soil

Phosphorus application?

Ok, I found out the main crop is on new growth, not much new growth...

I give it a good soaking every 3 days, and no fertilizer, I got in april

It needs some type of complete fertilizer to stay healthy and grow well. Unfortunately, young green growth is not cold hardy though so anything that grows now might get frozen this winter.

Maybe try half or quarter strength fertilizer a couple times before the end of the year and then the normal amount on the label next spring.

I put this on for now, a sprinkle of raw phosphorus, potassium and nitrogen

Nitrogen is a gas that makes up most of the air that we breathe so it can't be sprinkled. Potassium is a reactive metal that catches on fire when water touches it! So did you really put something in the container or are you just fooling around?

I saw on the other forum that you are 11 years old. Ask your parents for help with the fertilizer because it is really important for fig trees when they are in containers.

It's a supplement

What is the name written on the package?

Hope you are not using something from the garage that is supposed to be for lawns. They sometimes contain herbicides that kill trees and could also hurt you. It is important to read all of the directions and warnings on the package.

It's for hydroponics