@Kash1 When you import your model, import your texture(s) manually.
Then doubleclick on your material for your mesh (UE generates one, while import) and drag the texture into a textureslot.
Then drag Material on mesh.
Sry i am beginner and using Blender, but i always make it that way.
What i really like, is that you get an extra slot for each Material, you had created in your modeling program.
Greetings
Edit. My zombie says sry for confusing stuff. Load texture into Material, doubleclick on Mesh, drag and drop material into correct slot.