Hello, today I have tested the Chinese 8KW webasto in Power consumption directions. From my test it turned out that the maximum current consumption during startup is about 11A. The power supply should have some power reserve and I would aim for a minimum of 13A15A.
Sorry for the mistake in the Ammeter scale. 1 bar is 1 Ampere.

You can buy a webasto adapter here: https://s.click.aliexpress.com/e/_AlQnlk

See also my other films:
Chinese 8KW webasto test:    • Chinese garage webasto 12V 8KW Test U...  
How to connect the D3WZ webasto:    • How to connect the D3WZ webasto brief...  
2T Chinese water pump:    • Motor pump 1 "ALFA 2T petrol pump fr...  
Stupid Invention:    • Combustion meat grinder. Amazing home...