The tilix.art SSH server does not run on port 22 like most other tildes. Connecting to tilix.art on port 22 will connect to the host machine that runs tilix.art and helixnebula.cc. Use port 2020 instead. If you are using the commandline ssh program, specify your port by using the -p 2020 argument. For example:
ssh -p 2020 user@tilix.art
If connecting with another ssh or sftp software, look for an option to set your port to 2020
You will be prompted for your password. You can add your public key to ~/.ssh/authorized_keys to automate login.