Q.dying Tangerine tree
I have problem with my tangerine tree. Recently, my tangerine tree seems sick. I want this tree to survive. I do not know how to find a solution for my tree. It seems dying. Hopefully, I am wrong. Attached some pictures of the leaves, branches of the tangerine tree to show you its condition.
Thank you very much in advance.
GBU.
Sincerely,
Wiwy

It is quite difficult to really identify the issues with your Citrus tree in the image.
I have listed several links for you that may help identify the issues your are experiencing.
https://www.gardeningknowhow.com/edible/fruits/tangerine/tangerine-tree-care.htm
https://www.gardeningknowhow.com/edible/fruits/citrus/fertilizing-citrus-trees-best-practices-for-citrus-fertilizing.htm
https://www.gardeningknowhow.com/edible/fruits/citrus/curling-citrus-leaves.htmhttps://www.gardeningknowhow.com/edible/fruits/citrus/citrus-greening-disease.htm
https://www.gardeningknowhow.com/edible/fruits/citrus/controlling-citrus-thrips.htm
https://www.gardeningknowhow.com/edible/fruits/citrus/controlling-citrus-scale.htm
https://www.gardeningknowhow.com/edible/fruits/citrus/leaves-falling-off-citrus-tree.htm
https://www.gardeningknowhow.com/plant-problems/disease/cercospora-leaf-spot.htm