Package android.support.annotation does not exist

[rodrigoreal]

node_modules\capacitor-branch-deep-links\android\src\main\java\co\boundstate\BranchDeepLinks.java:5: error: package android.support.annotation does not exist
import android.support.annotation.Nullable;
                                 ^
node_modules\capacitor-branch-deep-links\android\src\main\java\co\boundstate\BranchDeepLinks.java:21: error: cannot find symbol
    @Nullable
     ^
  symbol:   class Nullable
  location: class BranchDeepLinks
2 errors

[paulhalfpenny]

We've run into this issue both on a React Native project, and an Ionic/Capacitor project as well. If you take a look at this SO question, the top answer provides a solution that worked for us:

https://stackoverflow.com/questions/40380519/error-package-com-android-annotations-does-not-exist

i.e. set your Android flags correctly and run jetify.