I assume you have installed Honeycomb and have confirmed it’s working?
Please provide the complete configuration YAML, correctly-formatted with the </> button, for the button that is giving the issue. Your post should look something like this example from the guide:
type: custom:mushroom-entity-card
entity: media_player.bravia_tv
layout: vertical
hold_action:
action: toggle
tap_action:
action: call-service
service: honeycomb
service_data:
buttons:
- icon: mdi:volume-plus #0
- icon: mdi:volume-minus #1
- icon: mdi:volume-mute #2
- icon: mdi:television-classic #3
- icon: mdi:television-classic-off #4
- icon: mdi:play-pause #5
If the formatting of your reply doesn’t look like that, please try again until it does.