I have an application and I would like to integrate it with your API. But my app is old and is in Ionic 3 and Cordova. It is possible to integrate via this documentation (https://docs.revenuecat.com/docs/ionic) as I tried and some errors occurred on my device
ionic info
Ionic:
ionic (Ionic CLI) : 4.12.0
Ionic Framework : ionic-angular 3.9.9
@ionic/app-scripts : 3.2.3
Cordova:
cordova (Cordova CLI) : 10.0.0
Cordova Platforms : not available
Cordova Plugins : not available
System:
Android SDK Tools : 26.1.1 (/opt/Android)
NodeJS : v10.22.0 (/home/alyson/.nvm/versions/node/v10.22.0/bin/node)
npm : 6.14.6
OS : Linux 5.4
One of the mistakes: