Reaching out directly to the owner’s email is always preferred.
However, sometimes you won’t be able to find it.
If you’re not able to find it, then reaching out to the general contact email they have will also work.
A lot of times the owner is also checking that email.
If he isn’t and an employee is responsible for it, often times they will redirect it to the owner.
Some websites use obfuscated email addresses to prevent spam, so try viewing the page source (Right-click > View Page Source) and searching for "@".
There are various tools that help locate professional emails: