Cannot establish connection

[Jellby]

On the server (remote):

wget https://lets.tunshell.com/init.sh -O - 2> /dev/null | sh -s -- T XXXX XXXX eu.relay.tunshell.com

cut: the delimiter must be a single character
Try 'cut --help' for more information.
Installing client...
Connecting to relay server...
[2026-07-28T08:41:39Z ERROR tunshell_client::server::dual_stream] Failed to connect via TLS, falling back to websocket: deadline has elapsed
Waiting for peer to join...
XX.XX.XX.XX joined the session
Negotiating connection...
Attempting direct connection to XX.XX.XX.XX
[2026-07-28T08:42:38Z ERROR client] Error occurred: Unexpected response returned by server: Close

On the client (local):

curl -sSf https://lets.tunshell.com/init.sh -o ${TMPDIR:=/tmp}/tunshell.sh && sh ${TMPDIR:=/tmp}/tunshell.sh L XXXX XXXX eu.relay.tunshell.com

Client already installed...
Connecting to relay server...
Waiting for peer to join...
XX.XX.XX.XX joined the session
Negotiating connection...
Attempting direct connection to XX.XX.XX.XX
Direct connection to peer established
[2026-07-28T08:40:15Z ERROR client] Error occurred: Error while authenticating with shell server

[Jellby]

Using the browser (and therefore a relayed connection) seems to work. Is it possible to force a relayed connection without a browser?