How to add material to 2d sprite

I am doing a simulation. I have a 2d sprite. I can’t add a material to it. I try sprite/default shader, but this time I can’t add texture. I will change the 2d sprite to 3d quad, but it will take a lot of work. Is there any way to add a texture to a 2d sprite?

Yes, you take your Texture and in its Texture Importer Settings (click on the .png or whatever in your Project tab), then you switch it to Sprite mode. Then it’ll generate a sprite, which can be plugged into a Sprite Renderer. Textures themselves don’t show up as sprites. A sprite has a texture, not the other way around.