Steps:

Login into the email with the GSuite Admin account.

Click on the 9 dots on the right-hand side of your Gmail to go to your Google account page.
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Click on your Account page.
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Now on the Account page, please click on Security and then 2- Step Verification under How you sign in to Google.

Please scroll to the bottom under the 2-Step Verification page and you will find the App Passwords option at the bottom.
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Please click on the arrow icon on the App passwords dialog box and you will be redirected to the next page where you can enter the App name.

Please enter the app name on the field and click on Create. Once you click on Create, a password will be generated with which you can set up the SMTP.

Now we need to update SMTP settings under the setting tab with the following detail

After adding the above details, click on the test button to verify the connection and then click on the update button to update the details. In case of a successful notification message will appear at the right top of the screen.