I am seeking a help when I am trying to open a link which is being redirected to external URL. Popup comes and asks me if I am ok to open a link in new tab.

On inspect Element, the following code is coming

<div class="ja_wrap ja_wrap_black"><div class="jAlert animated ja_default ja_md fadeIn" style="" id="ja_164642153664610723"><div><div tabindex="0" role="button" aria-pressed="false" class="closejAlert ja_close ja_close_round" aria-hidden="false">×</div><div class="ja_title"><div>You are opening a new window.</div></div><div class="ja_body">Are you sure you want to proceed?<div class="ja_btn_wrap optBack"><a href="" id="ja_btn_164642153664797026" target="_self" class="ja_btn confirmBtn ja_btn_green" tabindex="0" aria-hidden="false">Go to URL... https://www.twinstardevelopment.com/</a> <a href="" id="ja_btn_164642153664716093" target="_self" class="ja_btn denyBtn ja_btn_red" tabindex="0" aria-hidden="false">Cancel</a> </div></div></div></div></div>

Earlier the website was with another developer, and now I am confused how he has done this. I have checked the complete code but not able to find.

Screenshot is attached for the reference.

https://paste.pics/06978ad3aca67f06101afe79627eb0e0

Any help will be welcomed