FiveM Server Ubuntu

fivem.service

[Unit]
Description=FiveM Server

[Service]
Type=oneshot 
User=ubuntu
WorkingDirectory=/opt/fivem
ExecStart=/opt/fivem/fivem.sh
ExecStop=/usr/bin/tmux kill-session -t fivem
RemainAfterExit=yes

[Install]
WantedBy=multi-user.target

fivem.sh

#!/usr/bin/env bash

FIVEM_SESSION="fivem"
FIVEM_PATH="/opt/fivem"
FIVEM_DATA="$FIVEM_PATH/FXServer/server-data"

if ! tmux has-session -t $FIVEM_SESSION 2>/dev/null; then
  \tmux new-session -s $FIVEM_SESSION -n fivem -d
  \tmux send-keys -t $FIVEM_SESSION:fivem "cd ${FIVEM_DATA} ; clear" ENTER

  \tmux new-window -a -t $FIVEM_SESSION -n server -d
  \tmux send-keys -t $FIVEM_SESSION:server "clear ; cd ${FIVEM_DATA} ; /usr/bin/bash $FIVEM_PATH/FXServer/server/run.sh +exec server.cfg" ENTER

  \tmux detach -s $FIVEM_SESSION
fi