If you onboarded to dYdX using a wallet such as Metamask or Ledger, stark keys are automatically maintained for you. To recover your account, simply connect to dYdX using the same Ethereum address you onboarded with.
If you lost your stark key that was stored in a wallet (not in your browser on the dYdX website), you can’t perform any trade/transfer/withdrawal on L2, since they are all protected by signing with your stark key. However, you can still submit the relevant ForcedWithdrawal and ForcedTrade requests on-chain, using your Ethereum key, where the recommended flow is to make forced trade requests with users in order to close your position, then withdraw all your collateral with forced withdrawal.
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