Its possible to get the odata of project using sharepoint workflow?

Question

I am trying to do a http call to project odata _api/ProjectData/Projects, but when I run the workflow I always get access denied, even using app step. Here is an error bellow:

{"error":  
{"code": "- 2147024891, System.UnauthorizedAccessException",  
"message": {"lang": "en-BR", "value": 
"Access is denied.You do not have permission to perform this action or access this feature. "}} 
}