DT-06 WIFI. How to program with Arduino Uno
Are you wiring it to Arduino pins 0 &amp; 1? These are hard-wired to the other processor on the Arduino board that handles USB to/from your PC. There may be interference with the DT-06 unless you disconnect from your PC after upload. But then you'll need an alternate source of power to the Arduino.

You can pick another pair of pins and use the SoftwareSerial library (up to 9600 baud) to talk to the DT-06. Make sure Arduino and the DT-06 use the same baud-rate. You may have to experiment to find what baud-rate the device has now, in order to set it to 9600.

Update:


  Do i have to use any resistence?


Two sites I looked at described the DT-06 voltage requirement as:
"Working voltage: 4.5V~6.0V, TTL working voltage: 3.3V (compatible with 5.0V);", so you should be OK without voltage divider resistors.


  And what settings to make in arduino IDE before uploading code?


You won't need to change your IDE to upload code to the Uno.