Grant project access to a user

curl --request POST \
  --url {schemes}://api.upsun.com/users/{user_id}/project-access \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
[
  {
    "project_id": "<string>",
    "permissions": [
      "admin"
    ]
  }
]
'

{
  "error": "<string>"
}