@Karel ****
you can get a METV only at the Thai Embassy in The Hague, not at the consulate in Amsterdam.
You need to meet all requirements including show bank statement and a letter of approval from your work for your leave.
Or an unemployment statement from UWV.
Or KvK statement.
And a travelplan which says what other countries you be visiting in these 6 months since its a multiple entry they expext you to travel in and out.
Yiu can stay 60 days max on this visa and these 60 get renewed anytime you travel into Thailand before your end date of the visa.
Good luck.