What is professional fee plus expense?

Could you please clarify the meaning of "professional fee plus expense" in the context of financial transactions or cryptocurrency practices? Is it referring to a fee charged by a professional, such as a financial advisor or cryptocurrency expert, along with any additional expenses incurred in the process of providing their services? Or does it have a more specific meaning related to a particular type of transaction or service? I'm interested in understanding how this term is commonly used and how it impacts the overall cost of engaging with a professional in the field.