To find the private key of your Argent X account, please go to “Settings” and select the account you’d like to export the private key. (in this example screenshot below, “Account 1”).
Click on the “Export private key”, and this will allow you to export the private key. You can use this to import your Argent X account into Argent Mobile app, or to another Argent X instance (this feature is on testnet only).
PLEASE NOTE THAT SHARING PRIVATE KEY WITH OTHERS WILL RESULT IN LOSS OF FUNDS.
Please also note that you cannot export private key of your Argent Mobile and Web Wallet accounts, as they are designed for seed phrase-less experience.
If you are considering to retrieve private key of your Starknet account from other wallets, please consult with the respective wallet’s support team.