I am facing the issue on auth0 login & register

I have faced one issue in auth0 login when I checkmark the client_credentails in auth setting then I am not able to log in but I am able to register the user if it is unchecked that then I am able to log in but I am not able to register means visa versa code is working below I attached the code snip for react js & API call which I took from the network.

React Code

    <Auth0Provider
        domain={authConfig.domain}
        clientId={authConfig.clientId}
        client_secret={authConfig.client_secret}
        code={"AUTHORIZATION_CODE"}
        audience={authConfig.audience}
        connection={authConfig.connection}
        redirectUri={authConfig.redirectUri}
        useRefreshTokens={true}
        cacheLocation="localstorage"
      >
        <StrictMode>
          <App />
        </StrictMode>
      </Auth0Provider>

Network-API call code :

Request URL: https://dev-sa5zq41o.us.auth0.com/oauth/token

{
  "client_id": "xxxx",
  "code_verifier": "xxx",
  "grant_type": "authorization_code",
  "code": "xxx",
  "redirect_uri": "http://localhost:3000"
}