Add the repository URL under Supervisor → Add-on store → ⋮ → Manage add-on repositories:
The repository includes two add-ons:
- zigbee2mqtt is a stable release that tracks the released versions of zigbee2mqtt.
- zigbee2mqtt-edge tracks the
devbranch of zigbee2mqtt, so you can install the edge version if there are features or fixes in the dev branch that are not yet released.
For more information see the documentation.