I imported a material(texture) image in sketchup, aligned it on the model but when I tried to add it to the material in model section using the sample dropper tool it’s not working when I just move the sample dropper on the image it’s showing a red mark for unsupported or something
Did you import the image and leave it as an image? If so, right click on it and choose Explode. The image will then become a texture/material.
If you’re imported the image to use as a material in the first place, you would have to apply it to a face in the model but then it would be automatically shown in the in Model materials. You do not add images as textures with the eye dropper in the Materials panel.