How to add another option to a select type field starting from another field automatically?

ERPNext
1

I created a doctype in which one of the fields is of type select. Now I would like to create a button to automatically add other options to the options of the existing select type field and these new options can be selected afterwards.

2

That sounds pretty complex as you’ll need to edit the doctype via the API.

Can you change the select field to a child table? It would be much easier to add a button
to add a record to a child table.