Hello @JanB003. I do see that you have already called into our Support department regarding this issue. It looks like they informed you that when you edit the social media block, click on the social media icon that you'd like to update, and then put in the URL to your appropriate page. This URL should stay the same in all future campaigns.
I also did find the FAQ that you might have been looking for here. I'm sorry that you weren't able to find this earlier.