How I can get value for ajax data from text field?

Hi,
how I can get value for ajax data (function call Call ajax function) from text field?

I add class to my text field “my_keyword_field”

and in backend:

$keyword = $_POST[‘my_keyword_field’] ?? null;

// Return a success response

wp_send_json_success([“message” => $keyword]);

die();

}

but data not pas from front to backand…