Copy the song link by clicking on "Copy Link"

Paste the copied link in the browser's address bar

Click on the artwork

Hit "Download"

Log in to your Songer account

Open the Songs tab

Find the song with the artwork you want

Right-click the image

Select Open image in new tab. The image will open in a higher resolution.

Right-click the image again

Select Save image as… to download it

Log in to your Songer account

Open the menu and go to Songs

Find the song with the artwork you want

Long-press the image

Select Save image

Choose a download location if prompted