how to install? there is no installbutton

Sometimes the frontpage button to claim the giveaways doesn't work as it should.

Go find your order for Oaken here:
https://www.gog.com/account/settings/orders

If you don't find it, visit the direct link to claim the Oaken giveaway:
https://www.gog.com/giveaway/claim
Do it twice to make sure

Then you must find your Oaken order, Oaken in your library, and the install button for it.

ok solved now it apeared in library and i can play it thanks for the reply