If you create a new Ionic project and then add
@angular/fire to it and use AngularFire in your code, the code base will not build. This is because of a combination of versioning problems between Angular version 15 and AngularFire and Typescript.
See https://github.com/angular/angularfire/issues/3290 for full details.
I created a repo on github to address the issues “my way” (downgrading Angular and Typescript) so that my students could get back to work on their final projects… but I’m wondering if the Ionic team knows about this problem and has an alternative solution. (I think one solution is to not install Angular v15 when you start a new Ionic project.)