In the helionet wiki they showed a tutorial about how to get a free SSL in Zerossl. Now Zerossl is their own certificate company and doesn't provide more than 3 90 day certificates (or 1 90 day certificate renewed twice). But now you can get either unlimited 90 day GoGetSSL certificates from: https://freessl.space/ or you can get unlimited CertCloud certificates from: https://freessl.org/. Those unfortunately don't support wildcards or multidomains (a paid addon). If you want one that supports wildcard SSL then you can use the automated certificate bot from: https://www.win-acme.com/. They support multidomains and wildcards so you can get unlimited Zerossl issued SSL (or let's encrypt) for free.