Create common email send function

functions/email.ts

@@ -0,0 +1,29 @@
+export default async function (
+  email: string,
+  sendingKey: string,
+  subject: string,
+  template: string,
+  variables: {
+    [k: string]: string;
+  },
+) {
+  const body = new FormData();
+  body.append("from", "noreply@mail.carcrushers.cc");
+  body.append("subject", subject);
+  body.append("template", template);
+  body.append("to", email);
+
+  for (const [name, value] of Object.entries(variables))
+    body.append(`v:${name}`, value);
+
+  return await fetch(
+    "https://api.mailgun.net/v3/mail.carcrushers.cc/messages",
+    {
+      body,
+      headers: {
+        authorization: `Basic ${btoa("api" + ":" + sendingKey)}`,
+      },
+      method: "POST",
+    },
+  );
+}