Periodic general inspection (MOT, APK in Dutch)
Every motor carriage must be type-approved once before they are admitted on public roads. This is managed by the manufacturer. However, there is also a periodic inspection, the APK. It is not mandatory for most motorcycles. Only three-wheeled motorcycles with a weight exceeding 400 kg are subject to mandatory inspection. Think of trikes.

There is no APK requirement for most motorcycles. However, regular maintenance is recommended.
Inspection period three-wheeled motor vehicles
With these vehicles, the inspection period depends on the transmission (via a combustion engine or electric engine). The kind of fuel is also of influence on the inspection period.
Thus, petrol, alcohol (ethanol) or electric-powered vehicles must be inspected for the first time within four years of first admission. After this twice after two years and then every year. Most trikes fall within this category.
Vehicles with a different type of engine must be inspected within three years of first admission. After this every year. The APK must have been carried out before the previous inspection certificate lost its validity each time.
Inspection certificate
You will receive the inspection certificate after the APK. You must keep these well. In the Netherlands, you are not required to carry these with you, but in some countries you are. Both the driver as well as the owner or holder of the vehicle are responsible for the timely inspection of the vehicle and the state of the inspection certificate.
Regardless of whether or not your vehicle requires a general periodic inspection, it is wise to have a motorcycle serviced at least annually by a mechanic that is specialised in motorcycles. Especially if the vehicle is on the older side. A technical problem is more likely to end in a motorcycle crash.