It's best to do that at the server level, so in your nginx or apache config. The answer depends on which one you're using.
For instance, with nginx you could do it like
location ~* \.(?:css|svg)$ {
expires 1M;
add_header Cache-Control "public";
}
where 1M is one month. You could use -1 for forever, etc.
for Apache, something like
<filesMatch ".(css|svg)$">
Header set Cache-Control "max-age=31536000, public"
</filesMatch>
where 31536000 is the number of seconds until it expires.
Be careful on your cache times if you're not using laravel mix + versioning. Otherwise, if you change the css (for example), the browser won't reload it until the cache expires so new changes won't show up (unless the user clears their cache, or force-refreshes the browser - something you don't want to have to explain to your users)