ERPNext V15 integration with Shopify "fetch shopify locations" fail

Hello everyone, my 1st post here :innocent:

I’m trying to link my new ERPNext V15 installation with my new Shopify but struggle to “fetch shopify locations”. I can hit the button but nothing happens (like no fuction) :face_with_open_eyes_and_hand_over_mouth:. Therefore I cannot match the locations.

In postman I can get values from Shopify but I do not get a “reply” in ERPNext. Anyone an idea what I’m doing wrong?