iOS Zscaler App - trigger re-authentication

I’m working on an app, that requires Zscaler tunneling in-house, to reach a data path.
When I install my app on my device through a cable (first time use) Zscaler is triggered, I re-authenticate and all is good.

(let’s just make it clear that the app i registered in the interface and all that…it works)

However now I send it out to a bunch of testers, and none of them worked. Seemed like Zscaler was not triggered to re-authenticate.
Yesterday I looked at the testers phone, and all settings were correct, my app was supervised by Zscaler and when opening the app the little VPN logo showed up in the status bar.

however no connection - whne I installed same version of app through cable, when using the app first time run Zscaler was triggered.

So I am wondering if there is app end-point I can trigger in my code, i.e send the user to Zscaler app with the intent of re-authenticate .
or something like it ? I can’t seem to google any documentation on the iOS app.

Hope you can help.