To set a profile picture on Steemit you need an URL.
My first thought was I got a few nice photos on my Instagram account (gigaheiner feel free to follow me 🤗)
So here is how you do it:
-> Select the picture you would like to set as your Steemit profile picture.
-> Right click on it and choose "Seitenquelle" (in english it should be called "page source")
-> Just search that page for "jpg"
-> Copy that link and set it as your Steemit profile picture
-> Do the same with your cover picture
I hope i could help you 🤗