How much is the BTC sending fee?

Excuse me, could you please clarify for me the cost of sending Bitcoin (BTC)? I'm curious about the current sending fee associated with transferring BTC and how it might vary depending on different factors such as the network congestion or the size of the transaction. Is there a standard fee that's generally applicable, or does it fluctuate based on real-time market conditions? I'd appreciate any insights you can provide on this matter.