systemd script for notify-send fails with error "The connection is closed" - systemd

Question

I am trying to run a systemd timer. I am posting all the relevant files and the error below. I have posted the nodejs file but I tried with a simple shell script as well as explained in the Edit section.
/usr/bin/systemd/system/notification.service
[Unit]
Description=Show notification
After=systemd-user-sessions.service,systemd-journald.service
Wants=notification.timer
[Service]
Type=simple
ExecStart=/usr/bin/node /home/rounak/base/scripts/get-combined-notification.js
Environment="DISPLAY=:0" "XAUTHORITY=/home/rounak/.Xauthority" "DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus"
[Install]
WantedBy=multi-user.target
/usr/bin/systemd/system/notification.timer
[Unit]
Description=Show notification
[Timer]
OnUnitActiveSec=1m
[Install]
WantedBy=timers.target
get-combined-notification.js
const util = require("util");
const stdExec = require("child_process").exec;
const exec = util.promisify(stdExec);
const appNameForDunst = "CombinedNotification";
const executeScript = async (shellCommand) => {
return await exec(shellCommand);
};
const notifySendCommand = async (text) =>
await executeScript(
`notify-send -t 5000 -a ${appNameForDunst} " " ${JSON.stringify(
text
)}`
);
const commands = [
{
title: "Battery",
command: "acpi -b",
process: 'return output.split(",")[1]',
},
{
title: "Network",
command: "nmcli -t -f NAME connection show --active",
process: "return output",
},
{
title: "Workspace",
command: "xprop -root _NET_CURRENT_DESKTOP",
process:
'return ["view", "dev", "servers", "config", "notes", "av"][output.trim().substr(-1)]',
},
{
title: "Date",
command: "date '+ %a %d %b %y%nTime: %I:%M'",
process: "return output",
},
{
title: "Window Count",
command: "xprop -root _NET_CLIENT_LIST_STACKING",
process: 'return output.split("#").join("").split(",").length',
},
];
let final = "";
const handler = async (command, index) => {
const result = await executeScript(command.command);
const processOutput = new Function("output", command.process);
final = final + `${command.title}: ${processOutput(result.stdout)}\n`;
};
const main = async () => {
await Promise.allSettled(commands.map(handler));
notifySendCommand(final);
};
main()
journalctl -u notification
Jul 15 18:31:03 rounak node[3215]: Node.js v18.3.0
Jul 15 18:31:03 rounak systemd[1]: notification.service: Main process exited, code=exited, status=1/FAI>
Jul 15 18:31:03 rounak systemd[1]: notification.service: Failed with result 'exit-code'.
Jul 15 18:33:03 rounak systemd[1]: Started Show notification.
Jul 15 18:33:03 rounak node[4229]: node:internal/errors:845
Jul 15 18:33:03 rounak node[4229]: const err = new Error(message);
Jul 15 18:33:03 rounak node[4229]: ^
Jul 15 18:33:03 rounak node[4229]: Error: Command failed: notify-send -t 5000 -a CombinedNotification ">
Jul 15 18:33:03 rounak node[4229]: The connection is closed
Jul 15 18:33:03 rounak node[4229]: at ChildProcess.exithandler (node:child_process:387:12)
Jul 15 18:33:03 rounak node[4229]: at ChildProcess.emit (node:events:527:28)
Jul 15 18:33:03 rounak node[4229]: at maybeClose (node:internal/child_process:1090:16)
Jul 15 18:33:03 rounak node[4229]: at ChildProcess._handle.onexit (node:internal/child_process:302:>
Jul 15 18:33:03 rounak node[4229]: code: 1,
Jul 15 18:33:03 rounak node[4229]: killed: false,
Jul 15 18:33:03 rounak node[4229]: signal: null,
Jul 15 18:33:03 rounak node[4229]: cmd: 'notify-send -t 5000 -a CombinedNotification " " "Date: Fri >
Jul 15 18:33:03 rounak node[4229]: stdout: '',
Jul 15 18:33:03 rounak node[4229]: stderr: 'The connection is closed\n'
Jul 15 18:33:03 rounak node[4229]: }
Edit:
To rule out nodejs as the culprit, I used a shell script with one line notify-send "some" "some" instead of the nodejs script. I get the same error in journal: sh[2607]: The connection is closed