Good question. I love helping out with formatting things.
Are you on a PC or Apple thingy?
If it is a PC, then on your keyboard if you hit the Windows button on your keyboard (it's bottom left on my keyboard but it could be anywhere) - you are looking for a button with 4 squares in it. In the search box at the top type in: "Character map". Four across and 6 down should be the © symbol. Click on it, press select, then copy, then go into your Medium article and press paste. The rest should be easy, but if not get back to me, and I shall try and go into more detail.
If you have got an Apple thingy, try Alt/Option G. Hope that helps. And so very glad you enjoyed the article. It means so much to me if someone says I have made them laugh. A🙏💚