Search engine can't be registered

hello i downloaded api pluging but when i try to send register request every time i got this error

Search engine can't be registered

the data i used is

{
  "ConfirmPassword": "123456",
  "Email": "aa@aa.com",
  "Password": "123456",
  "LoginAfterRegistration": true,
  "ConfirmEmail": "aa@aa.com",
  "Username": "azzam",
  "TimeZoneId": "5",
  "VatNumber": "",
  "Gender": "m",
  "FirstName": "azza",
  "LastName": "m",
  "Company": "",
  "StreetAddress": "",
  "StreetAddress2": "",
  "ZipPostalCode": "254",
  "City": "mk",
  "County": "sa",
  "CountryId": 256,
  "StateProvinceId": 5,
  "Phone": "",
  "Fax": "",
  "Newsletter": false,
  "CustomerAttributes": {},
  "GdprConsents": {}
}

Hello Azzam,

Can you please share a screenshot of error and can you please confirm that you are using our API plugin?

Best regards,
Atul