From https://once.com/writebook

app/javascript/helpers/form_helpers.js

@@ -0,0 +1,9 @@
+import { FetchRequest } from "@rails/request.js"
+
+export async function submitForm(form) {
+  const request = new FetchRequest(form.method, form.action, {
+    body: new FormData(form)
+  })
+
+  return await request.perform()
+}