From the settings page, press the ‘Payment Routes’ button:
The payment routes page enables you to choose how you wish to receive a certain currency:
If you want to receive GBP as Bitcoin, just click on ‘Receive British Pound’ (This is set for you by default). If you choose ‘My BTC account’ instead, Bottlepay instantly converts all incoming payments (no matter the currency) to bitcoin. Any time you receive money, it will be redirected to your Bitcoin account.
This could be done in any way between currencies, you could configure a payment route so that all EUR you receive is automatically converted into Bitcoin or vice-versa.