Tree has lost most of its leaves. There is still fruit on tree however.
Tree Loosing All It’s Leaves
Certified GKH Gardening Expert
I'm not sure what tree you are having trouble with but I'm guessing a citrus tree.
Please let us know if it is a different type of tree.
The most common cause of a citrus tree losing leaves is temperature fluctuation.
Here is a link with some possible reasons.