Signup/Login integration of Chatting app with website/QRcode module integration

The source code of chatting app(Firebase), and, QRcode app are available.
And, there are SNS website establisehd with CakePHP.
Please help me in below job.
1. Integrate Signup/Login of Chatting app with website
2. QRcode module integration
* Chatting app info: https://play.google.com/store/apps/details?id=com.verbosetech.yoohoo
* QRcode app info: https://codecanyon.net/item/qr-code-barcode-scanner-and-generator-max-admob-ads/22818678
* Website info: https://www.pharmatalk.kr/

* Please see the attached ppt, first.

Budget Suggestion by twp steps ( 1st step; Website integration, 2nd step:QRcode integration ) is
required.

Thanks.