Need help with pto to combine

[blue4x4ford]

I'm trying to harvest my corn, i have a 90ft corn header that attaches to my harvester but i keep getting a error saying i need to attach a pto to my harvester first when i try to turn on the harvester. i have googled, searched the forums on steam/farming simulator but cant find anything so i'm trying here. any tips?

https://imgur.com/8IHaQeV

https://imgur.com/wJewWQu