Steps:

1. Instal Ibexa 4.5
2. Follow the documentation on creating form attribute (https://doc.ibexa.co/en/4.5/content_management/forms/create_form_attribute/)
3. Create new form
4. Add field 'Checkbox with RichtextDescription' to form
5. Open field settings

Result:
RichText editor not working in field settings, only text 0 words 0 characters is visible.

Expected result:
RichText editor is visible and working.

Note:
There is a typo in the documentation, in the snippet that is to be added to config/service.yaml in line 6 is:

  - { name: ibexa.form_builder.field_mapper }

This causes error: Could not find Ibexa\Contracts\FormBuilder\FieldType\Field\FieldMapperInterface for type checkbox_with_richtext_description
When this line is changed to:

  - { name: ibexa.form_builder.field.mapper }

error is no longer logged.