Read this as an example :

https://www.reddit.com/r/FreeGamesOnSteam/comments/foysu5/steamdlc_endless_legend_guardians/

Lots of people having the same issue.

It either says "Oops, you don't have Endless Legend yet ,get  it for free now."

or

"Incorrect login" ,on steam page.

Hope you can fix it.

Maybe just give us steam keys ,if you want to give us something ,instead of this convoluted process that one or two  publishers seem to enforce these days.

Ubisoft being another prime example.

Hello humpy,

To redeem the Guardians DLC, you must already have Endless Legend in your steam library and not just the Free To Play version.
It seems that the error message was confusing so we have updated it :)

Can confirm that you need to have a valid copy of endless legend on your account to get the dlc

Not clickbait at all then.

lastninja wrote:

Not clickbait at all then.

Not an entitled child at all then.