ippsec-tmux

# create or add this to ur ~/.tmux.conf 

#set prefix
set -g prefix C-a
bind C-a send-prefix
unbind C-b

set -g history-limit 100000
set -g allow-rename off

bind-key j command-prompt -p "Join pan from:" "join-pane -s :'%%'"
bind-key s command-prompt -p "Send pane to:" "join-pane -t :'%%'"

set-window-option -g mode-keys vi

run-shell /opt/tmux-logging/logging.tmux

In tmux 3.1c+

Change these lines :
bind-key j command-prompt -p "Join pan from:" "join-pane -s '%%'"
bind-key s command-prompt -p "Send pane to:" "join-pane -t '%%'"

To this :
bind-key j command-prompt -p "Join pan from:" "join-pane -s :'%%'"
bind-key s command-prompt -p "Send pane to:" "join-pane -t :'%%'"

Reference : tmux/tmux#1256 (comment)

@h4n0sh1 cheers mate, I've updated

Spelling mistake:

Change "Join pan from..." in line 11 to "Join pane from..."

:)