Go beyond postman

hi

it works in postman but i got an error when i use in a php file this php curl snippet

i got this response

{
“error”: {
“message”: “The request is missing a required parameter, includes an invalid parameter value, includes a parameter more than once, or is otherwise malformed. Check the "grant_type" parameter.”,
“code”: 400,
“data”:
}
}

i threw my head against wall for a long time

help woulb be so much appreciated

regards