What is crowdchange service fee?

Excuse me, could you please clarify what exactly is meant by the "crowdchange service fee"? I'm trying to understand if this is a fee associated with a specific cryptocurrency transaction, a service provided by a platform or exchange, or something else entirely. Is it a percentage of the transaction amount, a flat rate, or does it vary depending on certain conditions? Also, how does this fee compare to similar services in the cryptocurrency and finance industry? Thank you for your time.