I had this exact same error, problem was that I was exporting the component as:

const Component = () => { Swal.fire({ //configs... }) 

export default Component;

I deleted that last line and changed to:

export const Component = () => { Swal.fire({ //configs... })

And everything started to work again.

1. So you need to first make sure of that you are including the required css & js files in angular.json/angular-cli.json (depending upon your ng version)

  "styles": [
        "../node_modules/sweetalert2/dist/sweetalert2.css"
      ],
      "scripts": [
        "../node_modules/sweetalert2/dist/sweetalert2.js",
      ],

2. then, in your component, you can import it like this

import swal from "sweetalert2";

3. And in your component you can use it like this

swal({
     type: 'success',
     title: 'your message',
     showConfirmButton: false,
     timer: 1500
   });