If you are planning to go,you need to apply online for an Evisa.
Enter passport number,Dob,Parents names and entry date and pay $20.
At the moment you can still pay for the old style visa on arrival as they are allowing the tourist season to end after the summer.
But advices to do the Evisa in case Customs are not kept up to date.
There will be booths to get the Evisa at the airports.
To avoid delays and missing connections and resort transfers it is better to get it before leaving the UK.