Compatibility summary
You will need a travel adapter in Lesotho; plug types used there differ from Netherlands.
Plug comparison
Netherlands plug types: C F
Lesotho plug types: M
There is no common plug type between Netherlands (C F) and Lesotho (M). You need a travel adapter.
Voltage comparison
Netherlands: 230V, 50Hz
Lesotho: 230V, 50Hz
Voltage difference is within a range many devices tolerate; check your appliance label.