Pinch to Zoom within an Web-Object

i write an e-book learning app with a lot of html content.

i would like, that the user is able to zoom-in and scale the complete content (text, images an so on…) like a “normaly web-.browser” using the pinch gesture.

i have learned that , if i use an ionic page with ion-content , then i have to use the gesture controller and a lot of ts-code to realize a pinch-to-zoom function.
basically it works - but it works very jerky and not smooth.

so i have tried to take a web-object within the ion-content and load dynamicly the content in this object.
and i had hoped, that the user can now pinch-to-zoom in this object, like a normally webbrowser function - but it did not work!

is it possible, that a user can use gesture, like pinch and pan in a web-object without programming ts in ionic ??

thanks everybody for an imput and help…