Function withUtm

packages/email/src/utm.ts:9–15

(url: string, campaign: string)

 * - utm_campaign: the specific email/template (distinguishes emails)
 */
export function withUtm(url: string, campaign: string): string {
  const next = new URL(url);
  next.searchParams.set('utm_source', 'openpanel');
  next.searchParams.set('utm_medium', 'email');
  next.searchParams.set('utm_campaign', campaign);
  return next.toString();
}