I am planning to fly into FNA and make a further transfer with Kenya Airways to ACC. Just wondering due to the tiny size of the airport, if there is anything like a transit area allowing me to transfer from the arrival to the departure part of the airport.

Alternatively do I have to go through immigration and then get to the departure side (basically leaving airside)?

Travelling with hand luggage and having a transit time of 65 minutes. Visa is available for Sierra Leone and will be holding a boarding pass already (online check-in)