EmailJS is a cloud-based email delivery service that allows you to send emails directly from your client-side JavaScript code without the need for a server-side implementation.
Firebase is a Google-backed application development software that enables developers to develop iOS, Android and Web apps.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
HTTP/3 is the third major version of the Hypertext Transfer Protocol used to exchange information on the World Wide Web.