Below is a breakdown of the fees depending on if you are the lender or a borrower.
JPG Lending fees
The main fees for lending are 1% to the lender and 1% to the borrower.
Cardano TX fees
Outside of this are the standard Cardano TX fees, which usually run around 0.3 - 0.4 ada per Transaction.
minUTXO fees
There are some minUTXO fees charged depending on if you are lending or borrowing, these are either ~1.8 ADA or ~3.5 ADA and are labelled in the breakdown when building a transaction. This ADA will be refunded upon loan repayment, default, or cancellation (minus JPG lending fees).
Why do we need to make a deposit on these requests?
The refundable deposit is required by the lending protocol to function. It covers the minimum UTxO requirements needed by the Cardano network for the contract to be able to hold all the necessary assets and data.