I got error Api key is in valid during call User Management API

Hi everyone,

I’m working on User Management API: Authentication for API Access

I’m calling this API:
https://usermanagement.adobe.io//v2/usermanagement/organizations/A139DC7957D898C77F000101@AdobeOrg/users
with Headers:
Authorization: Bearer access_token
x-api-key: Client ID from Developer Console

But I’m getting this error message:
{
“error_code”: “403003”,
“message”: “Api Key is invalid”
}

Please help me on this.

Thank you,
Dustin