Re: how can I create a pause of 3 sec?

You can use a setTimeout: some examples - jQuery setTimeout() Function Examples

See screenshot

1. Somewhere along you transition add a Timeline action {}; Ctrl/Command + T

2. Add snippet as captured. Comments added to clarify.

    - force a stop() action of the symbol playhead at the same position as the trigger () call;

    - then use setTimeout to pause for 3 secs (3000);

    - once the 3 sec pause is up, resume play();