Once a hunter applies to one of your bounties, the bounty will appear on the Applications tab. Applications are grouped by bounty, allowing you to easily view multiple applications for the same bounty.
Click Escrow to accept a hunter's application for a given bounty. If you selected an ERC-20 token for your bounty, an Increase Allowance page will pop up directing you to allow the Cornucopia contract to transfer the bounty tokens into the contract. After choosing to either approve Cornucopia always or just for this escrow, an Escrow page will pop up where you can then elect to escrow the bounty tokens. If you selected ETH, then you will immediately be taken to this Escrow page. This will pull up your wallet to confirm the transaction, escrowing the amount of the tokens you specified when creating the bounty.
After escrowing funds, your bounty with the hunter's application will move to the In Progress tab.
If it is past the end date you set in the original bounty and the hunter hasn't submitted their work, then you can refund yourself the escrowed funds by clicking on Refund and confirming that you want to refund yourself. This will remove the funds from escrow in the contract and send them back to you.