Licence file not being picked up by ImageSharp

[Gavin-Williams]

I've placed the sixlabors.lic file in my project folder, and set the file to 'Copy if newer' (though I think that's probably not the correct way to use it, because I wouldn't want the license file to go with the output), but I'm still getting the error message
`No Six Labors licence found"

The error message goes on to suggest I ...

Set $(SixLaborsLicenceKey)
Set $(SixLaborsLicenceFile)
add 'sixlabors.lic' file to the project/workspace.

I don't know what any of these things mean. These look like VSCode concepts to me. I'm using Visual Studio.

Checking the docs again, it says "Place the supplied file in the directory that contains the project file" - I've done this.