Make sure you include the correct headers in your requests.
For GET functions, you need to make sure you include the "Authorization: Bearer ACCESS_TOKEN" header as follows:
curl https://app.workramp.com/api/v1/users \
-H "Authorization: Bearer ACCESS_TOKEN"For POST or DELETE functions, make sure you add the "Content-type: application/json" header as follows:
curl https://app.workramp.com/api/v1/guides/80afd844-fc64-11e6-8eb3-02dcdaae3a92/assignments \
-H "Authorization: Bearer ACCESS_TOKEN" \
-H "Content-type: application/json" \
...