Hi
With all your project on the timeline click the + sign at the left end which follows Sequence 1 x This will create a sequence of the whole project and place it in the sequence bin. At the same time it will empty the timeline.
Open the sequence bin and you will see Sequence 1
Right click this file and select Save Sequence Audio as New File.
This will create an audio wav file in tha audio bin and a copy in the folder designated in Options/Disc
Nat