ConnectionSettings cs = new ConnectionSettings(); 
cs.ExecutionMode =  
    TDAPI_EXECUTION_MODES.EXECUTION_MODE_INTERACTIVE; 
    
cs.BasicAuthHeaderMode = 
   TDAPI_BASIC_AUTH_HEADER_MODES.HEADER_MODE_ONCE;
   ...      
cs.SetWebServerCredentials("login", "pass");  

// import to OTA Connection      
TDConnection otaConnection = new TDConnection();      
otaConnection.ImportConnectionSettings(cs);

// connect to ALM server
otaConnection.InitConnection("http://<server URL>/qcbin");