Whatsapp Click-to-Chat "Couldn't open link" Error Chrome Android/iPhone
If you use https://api.whatsapp.com/send instead of https://wa.me/ you don't need to specify a phone number.
e.g
https://api.whatsapp.com/send?text=Your%20Custom%20Text
It seems that chrome does not accept click to chat without a number specified. Once there's a number in the URL it works just fine.
Unfortunately I did not find a hack to get around it. Neither of this worked:
https://wa.me//?text=Hello%20World
https://wa.me/0/?text=Hello%20World
only if a proper number is specified it will open WhatsApp, but has the recipient already pre selected (the number we provide).
I tested it for a client about 2 weeks ago, when it still worked. So the last update of Chrome (from Aug 26) seems to be the problem...
The best is to use the custom url scheme format. Universal links do not work well with native clients
whatsapp://send/?phone=&text&source&dataIt will work without phone number also.
My issue on a recent breaking-change: Universal links stopped working
There was a great blog post about the issue, however it is already outdated and proposes a php specific solution (nevertheless might gives you a good idea, how to think about the problem)