Getting popup blocker message in iOS app

Hello,
When I have filled my card detail in payment page and then click on proceed button a new window opens for OTP. this functionality working fine on web. But In case of iOS app Instead of opening new window of OTP a pop-up is opening with below mentioned text message.

Error message- Pop-up Blocker is enabled!
Please add this site to exception list.

I tried with setting change and of safari and I also added url into the "Link handling" section.

Please help !!