How to extend the AdminApp and add column to the backend list view for content items?
How to add taxonomy column for content items?
How to add classification fields to the backend page list view for a custom dynamic module, so taxonomies associated with content can be seen?

Part 1 - Admin app extensions application side

1. Set the admin app extensions application to start developing the extension as per below documentation:
https://github.com/Sitefinity/sitefinity-admin-app-extensions

2. When you open the admin app extensions application folder in Visual Studio Code, you will see in the solution explorer, folders with extensibility endpoints as below documentation:
https://github.com/Sitefinity/sitefinity-admin-app-extensions?tab=readme-ov-file#extensibility-endpoints

3. Below documentation explains the grid extension endpoint:
https://github.com/Sitefinity/sitefinity-admin-app-extensions-samples/tree/master/grid-extender#custom-grid

4. Add custom component in the grid-extender folder. In the attached example the files for this are:
 - classification.component.ts - code logic of the component - makes request to Sitefinity and gets the data of the classification field. The request is for a custom calculated property named "TagsProperty" (Below in "Part 2 - Sitefinity side" is explained how to create the custom calculated property).
 - classification.component.html - the view of the component - displays the data retrieved from the classification.component.ts

5. Add the column in the columns-provider.ts - attached example file.

6. Add the component in the index.ts - attached example file.

(The example components from the admin app extensions application can be omitted (like the image component)).

7. When finish developing, run the "npm run build:prod" command in the terminal and copy/paste the bundle from the dist folder in the AdminApp folder and restart Sitefinity, as explained in the documentation:
https://github.com/Sitefinity/sitefinity-admin-app-extensions?tab=readme-ov-file#deployment

Part 2 - Sitefinity side

Because each component in the AdminApp makes own requests to Sitefinity, created CalculatedProperty endpoint, which returns directly the title of the classification. Otherwise each component should have made one request to get the Id of the classification(because when the field requested via web service, the Id is returned) and one more request to get the title. Below article explains how to create calculated property which returns the title of a classification when requested via web service:

Taxonomies: How to return the titles of taxon items assigned to an item via a web service call