From 25 February 2022 the Dutch government has decided to open up the country and let go of most of the measures aimed to reduce the spread of the coronavirus. From this date all venues with fewer than 500 guests at a time no longer require anyone to show a COVID-19 Certificate (also known as coronavirus entry pass), to stay 1.5 metres apart, to wear a face mask or limit the amount of visitors. 

On 15 March 2022 the Dutch government will evaluate the remaining rules which are still in place including: the face mask requirement in public transport.

It continues to be advisable to wash your hands regularly, cough and sneeze into your elbow, do not shake hands, keep distance when possible, wear a face mask in crowded places, make sure there is plenty of fresh air and self-test regularly.

If you want to know which documents you need and which requirements there are to travel to the Netherlands please visit this site from the Dutch government.

Update
As of 25 March 2022, even more measures will be abandoned. You will no longer have to wear a face mask on public transport, but the advice against corona will remain the same. Wash your hands regularly, cough and sneeze into your elbow, do not shake hands, keep your distance if possible, wear a face mask in crowded places, make sure there is enough fresh air and do a self-test regularly.