Load Marketo Form Lightbox upon clicking specific link on landing page

<script src="//app-sjn.marketo.com/js/forms2/js/forms2.min.js"></script>
<form id="mktoForm_1886"></form>
<script>MktoForms2.loadForm("//app-sjn.marketo.com", "912-DWT-370", 1886);</script>‍‍‍‍‍‍

Hello Community! 

I would like to use the lightbox form code below (vanilla script from my instance) on a landing page. I know that using the script as-is will simply fire upon a page load, but I would like it to load when a user clicks a specific link.

I don't know enough about js in order to implement the script that way, so any suggestions would be super appreciated!

<script src="//app-sjn.marketo.com/js/forms2/js/forms2.min.js"></script>
<form id="mktoForm_1886"></form>
<script>MktoForms2.loadForm("//app-sjn.marketo.com", "912-DWT-370", 1886, function (form){MktoForms2.lightbox(form).show();});</script>