Create a dynasty not on my social tab

I play sims 4 on my iMac. When i download the Royalty and Legacy pack, I was able to create a dynasty by going into the social tab and creating it there. Now when I go to the social tab, there is no option to create a dynasty anymore. 
I uninstalled the game and reinstalled it on my iMac but I still don’t get the option to create a dynasty in my social tab. How can I fix this?