Cannot get past this error

[jonvaljean]

sweetalert2.js:2687 Uncaught TypeError: this.constructor.argsToParams is not a function
at Object.SweetAlert (sweetalert2.js:2687)
at Function.swal.withForm (swal-forms.js:15)
at HTMLAnchorElement. (product_view_script.js:2238)

Here is my link to sweetalert2
<script src="https://cdn.jsdelivr.net/npm/sweetalert2@8.9.0/dist/sweetalert2.js"></script>
Can you tell me, is swal-forms compatible with this version of sweetalert2 ?
Is there anything else I should be doing ?
Any help would be much appreciated.

From the documentation swal-forms is exactly what I need to make sweetalert2 useful as a rich data-entry device, but if I cannot make this work, I must fall back to another solution.
Thanks for your help.
Jon