ntfy-startup@.service

[Unit]
Description=Send a notification on system startup
StartLimitInterval=200
StartLimitBurst=5
Wants=network-online.target
After=network-online.target
After=multi-user.target

[Service]
Type=oneshot
Restart=on-failure
RestartSec=30
Environment=NTFY_URL=https://ntfy.sh
# see https://docs.ntfy.sh/emojis/
Environment=NTFY_TAGS="green_circle"
Environment=NTFY_MESSAGE="Startup time: $(uptime)"
#Environment=NTFY_MESSAGE="IPv4: $(dig @resolver3.opendns.com myip.opendns.com +short -4) - IPv6: $(dig @resolver3.opendns.com myip.opendns.com +short -6) - Local IPs: $(hostname -i)"
ExecStart=/usr/bin/sh -c 'curl -H "Tags: $NTFY_TAGS" -H "Firebase: no" -d "%H is online\n$(/bin/sh -c \"echo $NTFY_MESSAGE\")" $NTFY_URL/%i'

[Install]
WantedBy=default.target