I'm trying to create a fillable pdf from a html page with the free account of PDFlayer. An example of a field on the page is:

    Organisatie: 
    
    Ingevuld door: 
    

I use a url to generate the pdf:
https://api.pdflayer.com/api/convert?access_key=121afe68ac813e8987c26fa8e034f36a&page_size=A4&document_name=Pharos_Test_Begrijpelijke_Organsatie_04-09-2026.pdf&margin_top=0&margin_bottom=0&margin_left=0&margin_right=0&delay=1000&forms=1&secret_key=e32781d22e0393bafb2ce72e5b5e2374&document_url=https://vbi.pharos.nl/test-hbimo/results/pdf/1122212122

This creates the pdf but the fields are not fillable when opening this file. What wrong with this setup?