Mp3 Higher sampling

Im the beginer with audacity 2.02 so i record tracks at 44 100 kHz and converting file to Mp3. window (po pup) of this process inform me that Mp3 has 128 kbps sapmling. How can i extend sampling to 320 kbps?

In the export dialogue screen where you select MP3 as the format, click on the “Options” button.

it’s works, thanx a lot!