Lets Encrypt Certificates for DuckDNS

[jurassikdev34]

I installed Snikket as the guide. I portforwarded on my ISP router the ports on the guide. I added to my snikket.conf my duckdns subdomain ( chat.my-domain.duckdns.org ). But when I enter to this Snikket keeps loading for the certificates.

As I know, for getting a Lets Encrypt certiticates for a duckdns subdomain, you need a dns challenge with your token.

But where I put my token for Snikket automaticaly get the certificatess