Anyone here use the Rollbit crypto and understand the fees?

If you go by flat fee it says 0.04% for entry and exit. Does this mean it’s 0.04% total? For open and close? So 0.02% to open and another 0.02% to close? Correct?

Now how does the PnL fee work? Is it free to open and free to close as long as you lose the trade? If you make a profit then the fee seems to be variable. It’s like 0.01% per 0.01% profit and goes up linearly correct? I can’t find any documentation on this.