Pulsar222, greetings.
Unfortunately, a fellow user had encountered the
very same problem, and had submitted a review on the
product page for 'Inkborn' (as 'Verified owner' is missing from said review, it would seem that they may have sought (and had received) a refund).
Review title: There Is an Issue with Installation
After installing the game, upon execution, it launches Steam, and attempts to run via Steam. Then, the following message is displayed: 'there are no licenses'. I had purchased it on GOG.
As the observed behavior is clearly
not intended (and this game build should not have been uploaded to GOG by 'Acram Digital'), please, consider informing GOG support staff of this by
submitting a request.
Also, be sure to make reference to the review (written in Spanish) by user 'Ludwig0a' on the store page for Inkborn.