Thumber.co fails to authenticate

My managed host does not support ghostscript or imagemagick so I got a thumber.co subscription. When I enter the User ID and Secret I get the error “Failed to authenticate with given user ID and secret.” I copied and pasted these values and tried several times so I am sure that they are the same values that I was given.

Many thanks for this great plugin!

https://wordpress.org/plugins/document-gallery/