On your computer, open Gmail using the account you want to forward messages from.
In the top right, click Settings
Click Settings.
Click the "Forwarding and POP/IMAP" tab.
In the "Forwarding" section, click "Add a forwarding address".
Enter the email address you want to forward messages to. ( e.g. p181901234@mchk.edu.hk - example only)
Click Next Proceed OK.
A verification email message will be sent to that address. Click the verification link in that message.
Click the "Confirm" button.
Then go back to the settings page for the Gmail account you want to forward messages from, and refresh your browser.
Click the "Forwarding and POP/IMAP" tab.
In the "Forwarding" section, select "Forward a copy of incoming mail to".
Choose what you want to happen with the Gmail copy of your emails. We recommend Keep Gmail's copy in the Inbox.
Then click the tick box to activate the new email forwarding setting that you have created.
At the bottom of the page, click Save Changes.
Note: When your new messages are forwarded, messages from spam won't be included.
You can also click here to see the the original guide for automatic forwarding on Google:
https://support.google.com/mail/answer/10957?hl=en#zippy=%2Cturn-automatic-forwarding-on-or-off
That guide has a screencast of the steps to add automatic forwarding.