I have a Heath Zenith TR-0095-RX dorbell now. I need to know if the existing doorbell is digital or not.

Analog chimes consist of two plungers that make the traditional “Ding Dong” sound when the button is pressed. Digital
chimes play a melody tone when pressed and will feature a speaker within.

https://skybelltechnologies.zendesk.com/hc/en-us/articles/208219756-what-is-a-digital-doorbell-adapter-and-how-do-i-install-it-

The site also has a video of how to tell analog from digital doorbells.

Wireless units are Digital.