code: public Request<ClientGrant> create(String clientId, String audience, String[] scope) {
          Asserts.assertNotNull(clientId, "client id");
          Asserts.assertNotNull(audience, "audience");
          Asserts.assertNotNull(scope, "scope");
  
          String url = baseUrl
                  .newBuilder()
                  .addPathSegments("api/v2/client-grants")
                  .build()
                  .toString();
          CustomRequest<ClientGrant> request = new CustomRequest<>(client, url, "POST", new TypeReference<ClientGrant>() {
          });
          request.addHeader("Authorization", "Bearer " + apiToken);
          request.addParameter("client_id", clientId);
          request.addParameter("audience", audience);
          request.addParameter("scope", scope);
          return request;
      }
docs: Create a Client Grant. A token with scope create:client_grants is needed.
  See https://auth0.com/docs/api/management/v2#!/Client_Grants/post_client_grants
  
  @param clientId the application's client id to associate this grant with.
  @param audience the audience of the grant.
  @param scope    the scope to grant.
  @return a Request to execute.