How to change sweetalert button text?

You can use this approach

swal({
  text: "Start new case by",
  showCancelButton: true,
  confirmButtonText: "Select Patient?",
  cancelButtonText: "Speed Case?",     
  title: 'Title'
});

swal({
  text: "Start new case by",
  buttons: ["Select Patient?", "Speed Case?"],
});

here is the answer

 swal({
            title: "Are you sure?",
            text: "you want to Cancel Operation!",
            type: "warning",
            showCancelButton: true,
            confirmButtonColor: '#DD6B55',
            confirmButtonText: 'Yes, I am sure!',
            cancelButtonText: "No, cancel it!",
            closeOnConfirm: false,
            closeOnCancel: false
        },

hope it will work for you