How can I export a blender file into fbx and import it to unity so it will look and work the same way?

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I have a model in blender with texturas, animations and multiple objects. When I put the blend file in the unity project it works just fine, but when I export it as fbx and import it into unity everything is completely messed up. The texturas mess up, the animations don't wotk or only one of them and parts of the model apear rotated and not placed at their places. I tried every export and import settings, parented them to one empty object, changes rigging to legasy and went through all the animations to play them:

 Animation animation = GameObject.Find("Head").GetComponent<Animation>();
             animation.Play();
             foreach (AnimationState state in animation)
             {
                 animation.Play(state.name);
                 Debug.Log(state.name);
             }

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but still nothing works and everything is completely messed up..What do I do wrong?