Dynamically Change the Database name in the Powerbi desktop

Hi All,

   I am trying to  change the database name dynamically in the powerbi from the powerbi rest api call. I created parameters for server and database name  and use that in the query . I am trying to update the database name dynamically from the rest api. But , I am getting the same data  for the database which I given as the default in the parameter name. This is the code where I am updating the datasource name from powerbi rest api. I need to change the database name whatever I am giving as the input. Please help me to resolve this 

// Create UpdateDatasourceRequest to update Azure SQL datasource credentials
UpdateDatasourceRequest req = new UpdateDatasourceRequest {
CredentialDetails = new CredentialDetails(
new BasicCredentials(SqlUserName, SqlUserPassword),
PrivacyLevel.Organizational,
EncryptedConnection.Encrypted)
};
// Execute Patch command to update Azure SQL datasource credentials
pbiClient.Gateways.UpdateDatasource((Guid)gatewayId, (Guid)datasourceId, req);