Hello @karidrgn and welcome to the Community. I'm sorry, but there is no calendar or agenda app for the Sense 2. Your Sense 2 is preloaded with all available apps. Sorry. The instructions about the Play Store app sound like they are for the Pixel Watch.
Laurie | Maryland
Sense 2, Luxe, Aria 2 | iOS | Mac OS
Take a look at the Fitbit help site for further assistance and information.
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