JSFiddle - React, Tailwind, and code Playground

HTML

Form will submit on click, but not on enter key pressed, try tabbing to button and press enter ?

<br><br>
<form id="subscription_order_form" class=""  method="post" action="some_url"> 
  <button id="btn_order" type="submit">Order</button>
</form>

JavaScript

// Prevent the form to be submitted on ENTER
$('#subscription_order_form').keydown(function(e){
    console.log(e.which);
    if (e.which===13) e.preventDefault();
});

// Controll data
$('#btn_order').click(function(){
  checkMandatoryFields();
});


// Check mandatory fields before subitting:
function checkMandatoryFields(e){

  // Code for testing here

  // Set "error" message and abort submission
  if(msg.length > 0) {
    // Do something
  } else {

    //submit or trigger is not recognized as functions
    $('#subscription_order_form').submit(); //.trigger('submit');

  }
}