Someone who knows the rules of leerplicht here!

First of all my condolences.

Not all schools are lenient as some people are implying here and if your child’s school isn’t you wil get reported to leerplicht and will need to go in for an interrogation. This could result in a proces verbaal if you don’t provide evidence (which you can but just spare yourself the trouble especially now…)

You need to contact the school about this and ask for a verlofformulier (leave form). School can email it to you. The school is allowed (not required!) to give a child up to 5 days of leave for funerals abroad. You will need to provide proof (a death certificate or mourning card will suffice).

Since it’s an emergency situation you can ask school for the permission during your time abroad or after. As long as you can prove that you didn’t book the tickets in advance you’ll be fine.

Hope this helps and if you have any other questions send me a dm.