Here's why you need an adapter
The outlet and plug type used in Swaziland is M. Take a look at the picture below to see what this plug type looks like.
Voltage and frequency Fiji vs Swaziland
All outlets in Fiji provide a standard voltage of 240V with a frequency of 50Hz.Voltage: 240V Frequency: 50Hz
All outlets in Swaziland provide a standard voltage of 230V with a frequency of 50Hz.Voltage: 230V Frequency: 50Hz