Random post url displayed in top left, but no post loading

Hey! Thanks for making this plugin. I would love to get it to work, because it seems so simple.

I followed the instructions to the best of my ability:

1. install
2. activate.
3. add page, add custom field with random in the field and whatever number in the Value field.

This is what I get:

https://poemsforall.com/random/

Instead of the post showing up, I get a random post url in the top left and no post. Is my theme interfering or is the plugin not working?

Thanks.

https://www.ads-software.com/plugins/wp-random-post/