/Reactjs fetching bringing a 405 status code in browser

I am developing a react app over DHIS2 and data online that is structured like: I am trying to update the whole attributeValues Node. I’m using a fetch request, but getting 405 method not allowed What do you suppose i’m doing wrong. This is the fetch post request i wrote. If the question happens to be a duplication, please direct me to the possible already existing solution. Regards. Answer so the issue got resolved. I don’t know if its the DHIS2 system or something, but I can’t update just one node of an indicator, also because POST is for creating