Hi @Dg89,
Greetings from the Roku Community!
We're glad to assist you with your inquiry. When and where did you purchase your Roku device? If your back plate or mounting bracket broke and your Roku device is still under warranty, please check Roku's return policy and step-by-step instructions for returns and warranty replacements for more details. This way, the whole Roku device will be replaced together with the broken back plate or mounting bracket. We do not have a separate accessory for the back plate or mounting bracket as of the moment; we can only recommend checking from 3rd party retail stores.
If you need anything else, please let us know.
Kind regards,
Eunice
Eunice L.
Roku Community Moderator