Start with a chord progression or tune you want to work on. On the soloist menu, select generate and play a solo.

Select a soloist.  There are a large number of styles to choose from.

On the soloist menu, select edit soloist track, then select copy to melody track.

To view the TAB:

Select the melody menu, » track type » guitar.

It's also interesting to note that you can also generate a chord melody:

melody menu » generate guitar chord solo.