Check out the Quick add plugin by @Christian
The repo for the plugin has some great tutorials on how to set up all kinds of scripts - among them, instructions on building a custom script to grab info from IMDB.
It’s not a browser extension, but does grab what you want from the site. It could be a good way to get what you need.
I won’t sugar coat it, this isn’t as simple as turning on a plugin - there’s some light coding necessary. But the instructions are fairly clear once you read through the important stuff. I recommend looking at the initial how-to instructions first to familiarize yourself with the plugin before diving into this specific script. Once you set it up, you shouldn’t need to tweak much unless you want to change things up.