audacity in epub

hello all
i am new to this forum, two days later i had found that audacity is used in epub3 for read aloud text as it is free and easy to use.
the use of audacity in epub3 is found as defining the clip (by marking the start and end time)and exporting the times.
i went through many of the tutorial but i could not understand anything.
i had imported the audio into audacity after that iam stuck…
please give me a solution
thank you in advance

Import your show onto the timeline, drag-select the portion you want and File > Export Selection.

If it’s difficult to find either selection point, you can drag select around the point you want, zoom in and play, drag select and zoom in and play until you see it, and place a label at that point. Tracks > Add Label.

Spacebar is play and stop.

Control E - Zoom into selection.
Control 3 - Zoom out slightly.
Control F - Zoom out to the full show.

Do the same to the other point. Another label. Zoom all the way out and drag between the two labels. They’re magnetic or sticky and will grab the cursor. File > Export Selection