Synchronization in two ajax

How can I merge these two ajax into one?

I'm doing a shopping cart that when I click the button to add in the cart, it appears in the div class = car_discount the number of items added and in the class div = result_company_selected_id a confirmation.

The problem is that when I add the items, the div class = car_count sometimes does not change the value.

//Executa em cada form:
$('.formAjax').on("submit",function() {

    // Pegar o ID do formulário para depois:
    //Captura o elemento que sofreu o evento de "submit"
    const formDetails = $(this);

    var formID=formDetails.data("formid");

    //Remove a palavra quitar_ e deixa somente "debitoX"
 $('#loading').html('<img src="../images/45.gif"> loading...');

    $.ajax({
        type: "POST",
        url: 'add.php',
        data: formDetails.serialize(),

        success: function (data) {
            // Inserting html into the result div
            $('.resultado_empresa_selecionada_'+formID).html(data);         
            $('#loading').html(data);

        },
        error: function(jqXHR, text, error){
            // Displaying if there are any errors
            $('.resultado_empresa_selecionada_'+formID).html(error);
        }
    });
    return false;
});




//Executa em cada form:
$('.formAjax').on("submit",function() {

    // Pegar o ID do formulário para depois:
    //Captura o elemento que sofreu o evento de "submit"
    const formDetails_mnicart = $(this);

    var formID_mnicart=formDetails_mnicart.data("formid");



    $.ajax({
        type: "POST",
        url: 'count_carrinho.php',
        data: formDetails_mnicart.serialize(),

        success: function (data) {
            // Inserting html into the result div
            $('.contar_carrinho').html(data);               
        },
        error: function(jqXHR, text, error){
            // Displaying if there are any errors
            $('.contar_carrinho').html(error);
        }
    });
    return false;
});

I tried it like this but it did not work out yet

//Executa em cada form:
$('.formAjax').on("submit",function() {



    // Pegar o ID do formulário para depois:
    //Captura o elemento que sofreu o evento de "submit"
    const formDetails = $(this);

    var formID=formDetails.data("formid");



    //Remove a palavra quitar_ e deixa somente "debitoX"
 $('.resultado_empresa_selecionada_'+formID).html('<img src="imagens/Rolling-1s-30px.gif">');

var ajax1 =  $.ajax({
        type: "POST",
        url: 'add.php',
        data: formDetails.serialize(),

        success: function (data) {
            // Inserting html into the result div
            $('.resultado_empresa_selecionada_'+formID).html(data); 





        },
        error: function(jqXHR, text, error){
            // Displaying if there are any errors
            $('.resultado_empresa_selecionada_'+formID).html(error);
        }
    });


var ajax2 =  $.ajax({
        type: "POST",
        url: 'count_carrinho.php',
        data: formDetails_mnicart.serialize(),

        success: function (data) {
            // Inserting html into the result div
            $('.contar_carrinho').html(data);               
        },
        error: function(jqXHR, text, error){
            // Displaying if there are any errors
            $('.contar_carrinho').html(error);
        }
    });

$.when( ajax1 , ajax2  ).done(function( a1, a2 ) {
   // a1 and a2 are arguments resolved for the url1 and url2.
   // Each argument is an array with the following structure: [ data, statusText, jqXHR ]
   var data = a1[0] + a2[0]; // a1[0] = "Got", a2[0] = " Success"
   if ( /Got Success/.test( data ) ) {
      alert( "All AJAX calls successfully gave responses" );
   }
}); 
});