Passing multiple parameters to my 'POST' ajax call to my webAPI controller > http 404 not found

I can successfully do an ajax call to my webAPI like this:

Javascript:

    $.ajax({
        type: "GET",
        url: "api/Breeze/DeleteMaterials",
        cache: false,
        data: { aa: 'aa', bb: 'bb' },
        dataType: "json",
        contentType: "application/json; charset=utf-8",
        traditional: true,
        success: () => { result.resolve(true); },
        error: (error) => result.reject(error)
    });

Web API:

    [System.Web.Http.HttpGet]
    public void DeleteMaterials(string aa, string bb)
    {
        // doing something here
    }

It works pretty well. The webAPI is reached and the value parameters are present. Now I don't want to keep a 'GET' call because here I'm performing a delete server side, I need wether a 'DELETE' or 'POST'.

I know the 'DELETE' call is not possible because it only accepts 1 parameter and for my case I need to pass 2 parameters.

So I try to replace 'GET' by 'POST' in my previous code and the webAPI is never reached and I get the HTTP error 404: not found.

I already searched a lot in all SO suggestions but none of them gives me what I need.

Any idea?

Thanks.