You can use Studio to add necessary functionality or develop a custom module
https://www.odoo.com/slides/studio-31

Hi,

You can easily add a new field to the Employee model in Odoo using Odoo Studio. Here are the steps:

1. Go to the Odoo Studio app and select the "Employee" model from the "Data Models" section.

2. Click on the "Fields" tab and then click on the "Create" button.

3. Fill in the details of the new field, such as the field name, type, and label. For example, you can name the field "employee_type", select "Selection" as the field type, and label it as "Employee Type".

4. In the "Selection Options" section, you can define the different options for the "employee_type" field. For example, you can add options such as "Full-time", "Part-time", "Contractor", etc.

5. Click on the "Save" button to create the new field.

6. Once the new field is created, you can add it to the Employee form view by going to the "Views" tab in Odoo Studio and editing the Employee form view.

7. Drag and drop the "employee_type" field from the "Fields" section onto the Employee form view.

8. Click on the "Save" button to save the changes to the Employee form view.

9. Finally, go to the Employee list view and select an Employee record to see the new "employee_type" field in action.

Hope this will help you
Thanks