Hey! That’s so cool that your betta is flaring. Your fish is a cutie! However that tank looks pretty small from the pictures - a betta needs to have at least a 3-5 gallon tank (with a little heater and partial water changes regularly). Any smaller and it can be very bad for their health… toxic ammonia from fish waste will poison the water very quickly.
also, it’s super fun to add decoration to the tank! That way, your fish is stimulated, and you get to see them interact with the decorations and maybe even flare at them!
Just some basic stuff to keep your fish healthy.

 

She needs a tank. Are you keeping her in a tupperware container? That looks cruel.

 

1 fish = 3 gal minimum