Your debt only goes down
Deposit you already hold and borrow USDC against them; their weekly yield pays your debt down automatically - it only ever decreases. Depositing ETH to mint new bonds is a projection for now: it needs DexFi's signature, which is not wired yet.
Connect a wallet to deposit bonds and try a loan that repays itself, on a test network. This runs on Base Sepolia against mock DexFi bonds that are worth nothing, and there is a faucet inside to get some.