What type of issue is it?
Wrong documentation
What article/section is this about?
https://docs.umbraco.com/umbraco-cms/tutorials/creating-a-property-editor
Describe the issue
In the 'custom property editor' instructions, in the 'Creating a Web Component' section, there is an example .ts file with an incorrect import.
The example shows
import { UmbPropertyEditorUiElement } from "@umbraco-cms/backoffice/extension-registry";
I couldn't get that to build in v15 until I changed it to
import type { UmbPropertyEditorUiElement } from '@umbraco-cms/backoffice/property-editor';