In the Grab merchant portal app, you are able to assign a PIN to your outlet. Assigning a PIN restricts access to menu editor, ad manager, and promo manage.
Once the PIN has been set, access to make changes to your Menu and Promotions will be restricted.
Grab's official article - https://help.grab.com/merchant/en-sg/360034147392-How-to-set-up%2Fchange-in-app-PIN-to-restrict-access
Setting up a PIN
Once logged in to your Grab Merchant Portal account...
Tap on "More" at the bottom right, and under "App Settings" click on "Set up a PIN"
Tap on "Set Up Now"
Enter a 6 digit PIN and Tap on "Next"
Changing a PIN
If you've already set up a PIN and would like to change it, the process is similar!
Tap on "More" at the bottom right, and under "App Settings" click on "Change PIN"
Enter your current PIN
Enter your new 6 digit PIN and Tap on "Next"