Very good question @texnixe It was the blueprint. I had also copied it from another thread and overlooked a translation. Thank you!
Which leads me to the question if there is a comprehensive blueprint/yaml guide somewhere? I find it pretty hard sometimes to understand the logic of the blueprint, especially for the page builder.
I think we have extensive guidance on blueprints, both in the guide, in the reference, in the examples and the Starterkit.
The page builder blueprints are a bit special, though (and the documentation in the plugin’s readme could probably be a bit more detailed, but documentation always takes time that the plugin author probably doesn’t have). Always keep in mind that these people develop this stuff in their free time (and for free in most cases).
For the most part, our main Kirby blueprint docs should help though. You might also want to study how to fetch values from the different types of field. Each field has a short intro how to get data in your templates that should help.
But if you use all blueprint features within your builder, it can get pretty complex. It often helps to define fields or blocks separately and reuse within the builder. @jimbobrjames has an example below.
The blueprint can get pretty hectic if you have more then a couple of blocks. I can strongly recommend making use of the Kirby’s awesome ability to re-use and extend fields.
So in your page blueprint you do something like this: