You can simulate a fermata by doing the following:

1.

Put the cursor at the chord where you want the fermata and press CTRL-F5 (Edit | Chord Settings). Choose the "hold chord" option (all instruments).
2.

With the cursor still on that chord, press F5 (Edit Settings for Current Bar) and set a % change in tempo to, for example, -15 or -20, etc., depending on the duration you want.
3.

To play the original tempo again, move the cursor to the next bar, press F5 and choose an appropriate % change in tempo (15, 20, etc).