I have not tested it yet, but it says “The API is disabled by Mercedes. This app will not work anymore” i’m surprised it hasnt been deleted from the store then
I foudn the following
But i’m completely undertalented to make a Homey version of it
The Home Assistant integration that you link to doesn’t use the official API but mimics the mobile Mercedes Me app. For the official API there’s another Home Assistant integration that works just fine, but is more limited.
Perhaps the Homey app is using a different/older API that has since been deprecated.
(FWIW, I’m using the one from Rene Nulsch and it’s great )