Thanks so much for your submission. As Vincent mentioned, additional info will help troubleshooting. I think our FAQ on this subject is also helpful for troubleshooting as well:
How do I access IMDb Freedive?
If you are in the US, you can instantly stream IMDb Freedive titles from your laptop or personal computer's web browser on the IMDb Freedive page and all Amazon Fire TV devices via the IMDb Freedive channel. Freedive is currently available on devices that support ad-supported channels. Freedive content is currently only available when streaming from within the United States and U.S. territories. If you are currently located within the United States or a U.S territory and are unable to stream IMDb Freedive content, please contact Prime Video support.
So sorry for the delay in our response. I've confirmed that based on the Prime Video System Requirements for Computers, your browser should be compatible to play Freedive titles on IMDb.
If you're still experiencing this issue, please contact Prime Video support for further troubleshooting and assistance in real-time via phone/chat.
Please let us know if we can offer any further help.