> For the complete documentation index, see [llms.txt](https://enappd.gitbook.io/ionic-taxi-booking-app-starter/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://enappd.gitbook.io/ionic-taxi-booking-app-starter/extra/firebase-functions.md).

# Firebase Functions (Ionic 4 version)

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This section is for the Ionic 4 version of this platform, where Firebase Functions were used to make the apps talk to each other. Ionic 5 version does not use Firebase Functions.
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