@vincentlistens @Netlify You can post to an form on @Netlify with JavaScript. The docs describe that here.
https://www.netlify.com/docs/form-handling/#ajax-form-submissions
Keep in mind that the endpoint is created if the buildbot sees an HTML form in your site, so if you don't want to expose the form in a page, add it to a dummy page.
My tweets and posts live here on my own domain these days.
You can explore them here and follow me on Mastodon instead of Twitter where I'm not currently active.