Yesterday I got that "Your connection is not private" message after trying to access my local website with .dev domain.
Luckily I was aware of the problem thanks to people from PHP Srbija who posted this article on their facebook page.
There is a simple way to do this - just type (thanks to the comment below):
valet domain test
This was my initial hack which is unnecessary because there is a simple valet command to change domains
Since I'm using Laravel Valet first thing I've tried was to update the package, but no luck, so these were the steps that worked for me.
cp /etc/resolver/dev /etc/resolver/test
Open valet config ~/.valet/config.json and change domain from dev to test.
Open dnsmasq config ~/.valet/dnsmasq.conf and change content to
address=/.test/127.0.0.1
Restart dnsmasq - not sure if this is required, but that is what I did
pkill dnsmasq
Restart valet
valet restart