import requests

url = "https://api.diga.io/v1/project/{project_id}/invitation/{invitation_id}/role"

payload = { "role": "admin" }
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.patch(url, json=payload, headers=headers)

print(response.text)

{
  "status": "error",
  "error_code": "INVITATION_NOT_FOUND",
  "message": "Invitation 660e8400-e29b-41d4-a716-446655440001 not found"
}