To forward email sent to a Google GSuite (GMail) address, log onto the Google GSuite Admin Console, then click on Apps -> GSuite then click on GMail (Not the checkbox, the actual GMail row / icon to the right of the checkbox – it’s kind of a bad interface design because it doesn’t look like you have any option other than to turn it off or on). You will then have a lot of configuration options for GMail. Scroll down and click on “Default routing”.
From here you can click Add Setting to create a rule that forwards email sent to a specific email address.