"I created an icon, but I wanted only the round part, but it was completed with square data due to a problem with the data.
So, I🥺 would like you to tell me how to round it using Photoshop💦. I'm going to put it on the Premier Pro after I've rounded it up."
All images are rectangles — you can't change that. The problem with yours is that you don't want the brown background. Instead, you want transparency. Here are a couple of thoughts:
When you create it in Photoshop, create and use layers for each part and start with a transparent layer. Don't work on the Background layer, as it does not support transparency. We can't see your Layers panel and don't know how you structured this.
JPEGs don't support transparency and will fill in transparent areas with a solid color. You didn't say what format you saved it in, and we can't tell from here. I don't use Premiere, so I'm taking a guess that PNG would be a good format to save in. Plus keep the layered Photoshop version in case there are changes.
If you need to fix this file, make a selection around the white circle, invert it, and delete the brown.
Does any of this answer your question? If not, please give more details so we can better assist.