You can stake rLP tokens in the Deep Farming Vault by following this guide.
Go to delta.financial and connect your wallet by clicking on "Connect Wallet" in the top right corner.
On the main page click on Vaults to open the Deep Farming Vault page. Navigate to the stake and mint section of the vault and press the "Stake rLP" button. Enter the amount of rLP you would like to stake or click "MAX". Then click the Stake button and confirm your transaction. After a few minutes the rLP Token section will display your staked rLP tokens.