Go to the edit page of an audio file.

Format the script so that each sentence/couple of sentences that needs to have pauses in between is in its own paragraph/speech section.

Click on somewhere empty on the timeline, and drag over all speech clips of interest to multi-select them.

Select the End pause button, and adjust its duration to let's say 1 second.

You have now applied a 1 second pause across all these speech clips.