I am building a Web chat application (PWA).

I have a chat input, which I would like to keep focus on even when the "send" button is clicked. So I want the keyboard to stay open even when a chat is sent, either by pressing a "send" button, or by clicking on the "send" in the mobile's keyboard itself. This is the behavior you get in messaging apps like Whatsapp, iMessage, etc.

Even though it works on Android as expected, but I can't make it work on iOS Safari / Chrome.

What I have tried so far is as follows:

Bind touchstart / mousedown event, call preventDefault and stopPropagation.
Additionally, I am also doing "preventDefault" on the click event.

How can I achieve this on iOS Safari with vanilla javascript + HTML?