Not sure if you figured this out, but I just did it on my site. I think what Paul meant is that you only followed Step 1, which gives you multiple options depending on how you want the reading time to appear.
You still need to do the following for the text to actually display on your posts:
Step 2 (Go to Settings > Advanced > Code Injection and paste the following into the Header...)
Step 3 (Change the design to your liking. Go to Design, click Custom CSS...). This step has 2 options for you.
I hope this helps!
