Adding a GTK application to startup using systemd.

Hello,

I'm trying to add a python GTK application I created to the startup using systemd.

In order to do so I created the following gatewayservice.service file:

[Unit]
Description=Gateway service
Requires=graphical.target
After=graphical.target
 
[Service]
Type=idle
ExecStart=/bin/bash /usr/bin/gateway_service.sh
 
[Install]
WantedBy=multi-user.target

I am able to manually start the service using

systemctl start gatewayservice

But when I try to add it to startup and reboot it doesn't launch automatically.

I think I'm getting the requirements wrong in the service file but I'm not sure what to put instead.