How do I host the backend of Phonegap app?

I am building a cross-platform mobile app for iOS and Android using PhoneGap and I am confused about how to host the backend. The app will have user accounts and a forum (implemented using PHPbb) so data needs to be shared across devices.

Through my research I have found the SQLite plugin for PhoneGap apps, and I know that PHPbb can sit on top of an SQLite database, but I am confused on two things:

• Can I implement user accounts using SQLite as it is not a client/sever database?
• If yes, is it possible to host an SQLite database using a BAAS solution like Firebase that my PhoneGap app can talk to using the SQLite plugin, and will it be compatible with PhoneGap build?

Firebase has realtime database and firestore database options. There is no SQLite option. Google Cloud Platform offers CloudSQL which allows for postgreSQL and mysql options.

Firebase hosting is designed to help you host your own custom functions and application backends. PHPBB requires PHP support (among other things) and firebase functions only support nodejs.

If you are looking to host an app like phpbb, look into launching a phpbb VM on google cloud platform as an option. https://bitnami.com/stack/phpbb/cloud/google

Firebase authentication is designed to allow you to support user accounts for a custom app backend.

How you decide to tie your app into phpbb will probably have nothing to do with firebase.