title: how open phonepe or google pay using upi deeplinking in ios using swift
body: <p>Im trying to integrate UPI payment in my app. i have seen some apps where they are providing google pay and phone pe buttons, if they are installed in the device. on clicking button, particular app is opening.
  I need to implement similar experience in my ios app.</p>
  
  <p>i have tried generating URL as specified in NPCI doc <a href="https://www.npci.org.in/sites/all/themes/npcl/images/PDF/UPI_Linking_Specs_ver_1.5.1.pdf" rel="nofollow noreferrer">https://www.npci.org.in/sites/all/themes/npcl/images/PDF/UPI_Linking_Specs_ver_1.5.1.pdf</a></p>
  
  <p>i tried using   UIApplication.shared.open(url, options: [:], completionHandler  to open the UPI app. every time its opening whatsapp only. </p>
  
  <p>How can we open phone pe / google pay app based on users selection without entering payer's UPI id.</p>