Truecaller button opens safari & not true caller app in ios11.2.6

I have integrated true caller sdk for iOS in my application. On click of TrueCaller button in ios10.3.3 user is navigated to TrueCaller app & once approved to continue user is navigated back to app, along with profile details. But on click of trueCaller button in iOS 11.2.6 user is navigated to safari & not to the TrueCaller app(Sharing screenshot of safari page)