The Datafund application uses Web3Auth (https://web3auth.io/) service as a sign in mechanism. If you are not using a wallet software to sign in, then your private key resides inside the application's web page only. That means in order to access funds from your account and make transactions, you need to export the wallet.
To do so, after you sign in, click on the user menu at the top right corner and select Settings. Inside the settings page click the Export Wallet button. A password window will show up where you need to enter password that will be used to encrypt your wallet's private key and export it securely that way. Once when you submit your password, automatic download will start. Your wallet will be exported to the wallet.json file.
Importing your wallet to Metamask
You can easily import your exported wallet to Metamask. Check this article:
