How to add a filter select box in top form ?

Hello,

I am using DataTables v1.11.2 via Yarn + Webpack with serverProcessing & Bootstrap 5.
I would like a select box filtering the query sent to server
Here are all the points I need:

• The select box appears in header form, between "Show X rows" and "Search"
  => I didn't find how to do that at all
• When requesting results to the server, the value always appears in query string
  => Using a function as ajax.data seems to do the job => https://datatables.net/reference/option/ajax.data
• The select box is always having a value, it has a default value and it uses it for the first request
• When selecting another value, the table immediately refresh and show new results
  => Using ajax.reload() should be ok => https://datatables.net/reference/api/ajax.reload()

My request seems very classic for me but I didn't find help on documentation for all points.
Have you any advice pls ?