How do I use my Photoshop ui?

Hi,

I made a health bar in Photoshop and want to use it as ui in my unity game. I saved it as psd then imported it into unity. Some odd things I've noticed is there was still a white background behind it when imported, even though I removed the background in Photoshop. Also I cant seem to drag it on my unity canvas.

How can I get this to work?

Thanks