In the song / preview panel / cover there is a "Search with browser" button which is used to manually choose a cover using the browser.

2023-06-15_180833.jpg

 

After clicking the button the default browser will open the cover overview found on google.

2023-06-15_180904.jpg

 

At this point click on the favorite cover so that the cover will be shown larger on the right and right-clicking there copy the direct link to the jpg or png image

2023-06-15_180928.jpg

 

Now close or minimize your browser and paste that link into the dialog that is pending

2023-06-15_180943.jpg

 

Note that the link must end in .jpg or .png for the cover to be downloaded