Why can I not add my own image to particle material?

Hello, I’ve made an 256x256 PNG-image with transparent background in Illustrator that I would like to use as my particle material, but it won’t let me drag it into the material box from my project folder. Are only some file types supported? How should I export it from Illustrator?

Thank you!

You cant drag a texture into a material slot. You need to create a material and assign the texture to that, then drag that material into the slot. Alternatively use the Texture module and drag it into that.