How do I disable the option to that automatically sends a message when I hit enter on my keyboard?

Because this is a big problem for me and my clients and it's really inconvenient since we mostly use a computer to communicate with customers so whenever we hit the enter key to start a new line in ends up sending the message.

And, as you can imagine, a lot of message get sent by mistake and only causes problems. I would love to have a solution where we can turn this setting off.

Thanks,

Paul Facey