How to send data from the field in the admin panel?

Question

Django

The model has CharField fields X and Y , both are displayed in the admin panel. The user fills in the X field, the entered data is used to create XML, after which the XML is sent, via a POST request to another site, the response is XML, the data from which is used to automatically fill in the Y field. The user cannot edit Y. Actually, how to implement it? Of particular interest is the part on the implementation of the button, which will be tied to the actions to receive and send data, as well as autocomplete the field.