Transparency does not work with Particle system

I'm pretty new to Unity and there is a problem that occured for me. Transparency is not omitted.
Sc of the shader of material used in Particle system.

 

Check your texture import settings: I don't think you are properly importing an alpha channel: you shouldn't be seeing the gray checkered pattern in the asset.

 

I tried to change settings in Import Settings but it does not seem to work. I checked "Alpha Is Transparency" and tied other setting too but nothing works.

 

Go find a png on the internet that you KNOW has transparency, and try that. I don't think your star has the transparency you think it does.

Here's one.

 

Thank you very much for help I was not thinking if the images I download even have trasnparent background just quick edit in gimp and everything works fine.