Hi folks, for my current project I have to extend the form fields on CMS -> Pages.

I've created a small Plugin which shows the new field. This codeblock creates the custom field (I know in each backend form, but not nessesary to solve my question for now).

        Event::listen('backend.form.extendFields', function($widget){

            $widget->addFields([
                'custom_field' => [
                    'label' => 'Custom Field',
                    'type' => 'text'
                ]
            ]);

        });

Allright, here is the big questions: How to save/update this field to the pages yaml-file?

Big thanks for helping me. Cheers.

Ok, found out, that I've forgotten to add settings to the field key^^

            $widget->addFields([
                'settings[custom_field'] => [
                    'label' => 'Custom Field',
                    'type' => 'text'
                ]
            ]);