Increase PHP's upload_max_filesize in Apache

I have a Laravel app and I need to increase PHP's upload_max_filesize, but rather than do this for the entire app I wanted to apply it to a specific route/location. I am running Apache 2.4.

In the past with something like WordPress I would put this in the Apache virtual host configuration:

<Directory /www/website.com/public/wp-admin>
php_admin_value upload_max_filesize 30M
</Directory>

However, with Laravel every request is routed through public/index.php using mod_rewrite, so there aren't separate files or directories per-se.

I have tried:

<LocationMatch /admin/>
php_admin_value upload_max_filesize 30M
</LocationMatch>

Which doesn't seem to do anything.