sign out of your lost device Gmail account : This article teaches you how to sign out of your Google Account on lost or stolen devices.
According to Howtogeek, have you lost your Android or iPhone smartphone? Have you lent your device to a family member but forgotten to sign out of your Gmail account? Do not worry; Google lets you remotely sign out of your Gmail account on any lost or stolen device. As long as you have access to your Gmail account, you can use Google’s privacy features to remotely exit any connected device.
sign out of your lost device Gmail account
To get started, open the Gmail website in your favorite browser. Click on your profile icon in the upper right corner and then select Manage Your Google Account.

Go to the Security tab and then click the Manage Devices button at the bottom of Your Devices.

There you will see a list of all the devices that are currently signed in to your account using Gmail or other Google services. Find the device you want to exit, click the Three-Point Button, and then select Sign Out.

Google will ask you if you are sure you want to sign out. This step removes the Google Account and all related data from the device. Once confirmed, click the Sign Out button to confirm.

If the selected device is online, Google will remove you immediately; But if you have lost your smartphone or tablet and the device is turned off or is not connected to the Internet, Google will delete the account as soon as it reconnects.
If you want to sign out of more devices, follow the same procedure in the Your Devices section of your Google Account page.