How to resolve the problem of this code? The ability to receive all values to the database?

I have validated it to send one or two or all three if the user checks the checkbox. My problem is I only receive one value even if the user checks all three.

This is is on laravel php framework, but I think it applies to all database logic.

This is MySQL data type

$table->string('category');

     function restorative() {
                    var x = document.getElementById("restorative").required;
                               
                      }

                    function esthetics() {
                    var x = document.getElementById("esthetics").required;
                               
                      }
                      function implant() {
                    var x = document.getElementById("implant").required;
                               
                      }

   <input type="checkbox" name="category" value="Restorative" id="restorative" onclick="restorative()"><label for="">Restorative</label>
        <br>
        <input type="checkbox" name="category" value="Esthetics" id="esthetics" onclick="esthetics()"><label for="">Esthetics</label>
        <br>
        <input type="checkbox" name="category" value="Implants" id="implants" onclick="esthetics()"><label for="">Implants</label>

via Chebli Mohamed