Unknown custom card in cast

[joachimcarrein]

I have read the wiki about what to try first before creating a bug report.

Which version of HA do you use?
2021.7.4

Which version of the card do you use?
via HACS - latest: 0.1.5

Describe the bug
When casting a dashboard to a google hub, it says the custom card is not found

Configuration of the card
Copy the complete configuration of the card, even if you think it isn't relevant.

type: custom:power-wheel-card
solar_power_entity: sensor.sma_current
grid_power_entity: sensor.p1_meter_active_power
production_is_positive: false

Dev console debug output
No clue how to get debug output on google hub cast

Expected behavior
The card being shown

Screenshots
If applicable, add screenshots to help explain your problem.

it is shown in the browser: