There are a few ways to export an image with a transparent background in Photoshop. The most common way is to use the Export As command. You can also use the Image > Transparency > Background command.
To save a transparent background in Photoshop 2021, use the Save As dialog box. Type the name of the file you want to save the background as, and click OK.
Some PNGs may not be transparent because of their format. PNGs are created as graphics files and are usually saved as an image with a resolution of 256×256. When you view a PNG on a computer, the images will be displayed in their original resolution but will be slightly blurry.