Yes, you can pay the money in sterling and have it converted into a lira account, and then withdraw it in sterling, although of course you could lose out doing this if the exchange rate changes drastically.
We were advised to put money in for a calendar month at a time. The interest is then compounded each month. For example, if you invested £1,000 and earned, say, £15 interest in the first month, then during the second month you would earn interest on £1,015, and so on, automatically. Withdrawals can be made after the first month.
Hope this helps.
Anne and Terry