On my monitor that is a trunk against a brown background. I can't even make a guess what kind of tree it is.
Inasmuch as there is no designated place where your tree is growing, beyond indoors I can't make seasonal recommendations,
The likely big three of malsai bonsai are: elm, fig, juniper. None of whom should be indoors in the northern hemisphere in August.
1. Check for and remove glued on rocks. They interfere with watering.
2. Go to bonsai learning forum here and read chop-stick watering posts.
3. Trees don't live where the ambient humidity is 20% or less, like indoors.