Annoucements created using Microsoft Azure Cognitive Services Speech Studio (speech.microsoft.com)

You can see the instructions here: https://github.com/OpenEdPakistan/speech

The contents of this zip archive are:
00a-Boarding.mp3
00b-Welcome.mp3
01-Taxi.mp3
02a-PreTakeoff.mp3
02b-Takeoff.mp3
02c-PostTakeoff.mp3
03a-SeatBeltOff.mp3
03b-SeatBeltOn.mp3
04-Descent.mp3
05-Landing.mp3
06-Landed.mp3
07-GoodBye.mp3

Play each of the audio files at appropriate times during the flight for a real-life PIA experience. You can also use the above files with a 3rd party software like LukeAirTool (https://flightsim.to/file/652/lukeairtool), 
FS Cabin Crew (https://fscabincrew.drubware.net/), etc.

If you want .wav files, you can use an online coverter like Cloud Convert (https://cloudconvert.com/)