The term FX swap means rolling an expiring currency forward into a new currency forward.
When you roll an expiring currency forward (or any forward, for that matter), you pay or receive the difference between the forward rate to which you agreed and the spot rate at expiration. If that difference is negative, you have a cash outflow.
You phone your bank and ask them if interest rates are high. You could also check Yahoo! Finance.
The level of interest rates doesn’t create the cash flow situation. The level of interest rate determines whether you lose a lot of interest or only a little interest _ when you have a cash outflow _.