I can't edit it for you (it won't let me), but I can walk you through how to do it .
1. Click on the little icon in the top right corner with your profile photo.
2. Click on your username to go to your profile.
3. Scroll to the bottom of your cover photo and in the bottom right corner will be a button that says edit cover.
4. Click on that and upload your picture using the little box that shows up. Then clock save.
This will now appear as your signature on all your posts as well as your cover on your profile.
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