I have a problem inserting the model into unity

hi i need help when i put the model in the unity (blender )so i got it somehow transparent from the sides what about it? Thank you in advance for your answer

 

Looks like triangles are flipped. Flip them if necessary in Blender3D.

In Blender, enable backface culling (google) and you can see which way the faces are pointed there so you can fix them all at once before coming to Unity.

 

Thank you