Open the Google app, Gmail, or any Google service you are signed into
Tap your profile picture in the top right
Select the Google account you want to sign out of
Tap Manage accounts on this device
Choose the account
Tap Remove account or Sign out
Confirm when prompted
On a web browser, go to Google account settings
Click your profile picture
Select Sign out or sign out of all accounts if needed
If you only want to stop using one account in Chrome, remove that account from the browser profile or sign out from the Google service you are using