Hi, I got confused in the beginning with the page parameter, but i think i have found the solution 
from the API explorer I understood there are two modes : https://api-platform.functionpoint.com/docs
application/ld+json (inclluding hydra) and standard application/json (which doesnt provide hydra)
SO the conclusion is the set accept application/ld+json in the headers
another universal conclusion: read the docs
please accept my humble solution if it has helped you
and btw i don’t have a clue why it would work in postman without this.
reg,
J.