I am also getting a recurring uncaught syntax error on line 61, but if I retype the opening bracket ("<") it seems to correct it until the next time it tries running it. I’ve looked through my code a few times and don’t understand why it believes it to be a syntax error.
You need to set your preprocessor to Babel, I don’t know if it’s the only thing missing, but that would be a big reason for which you get syntax errors for React
I’m doing a course from the blog. In codepen I have to use react dom as well. iealeen is right also. Here’s a post from Chuck in 2019. Getting started with react on codepen - #2 by chuckadams
So in the js settings (the gear icon) you should link to react,react dom, and babel. Read the post I linked to.
It is interesting to note that playgrounds are just HTML form text boxes that through JS magic get built into a webpage presented in an i-frame. So you should set things in the settings (behind the gear icon) for every project then things get put in their proper places on final assembly.