In case you ever forget your
MetaMask Extension credentials and you restore your wallet through the secret recovery phrase, then these additional accounts would not be re-added automatically. Only the primary account i.e. Account 1 would be re-added automatically and you need to re-add the rest of the accounts manually. Restoring an account through the MetaMask Wallet
By creating the new account, your previous accounts would be restored immediately, and to do so, here are the steps to be followed:
The first thing that you need to do is sign in with your
MetaMask Wallet password
When you get into your account, please click on your profile icon at the top
This is present in the MetaMask drop-down menu
Click on the "Create account" button and then name your account one more time.
