What is the fee for Dex?

I'm curious about the cost associated with using Dex. Could you please elaborate on the fee structure for this decentralized exchange? Is there a flat fee per transaction, or does it vary based on the amount or type of cryptocurrency being exchanged? Additionally, are there any hidden fees or charges that users should be aware of when utilizing Dex? Understanding the fee structure is crucial for making informed decisions in the world of cryptocurrency trading, so I'd appreciate your insights on this matter.