Finding login info for WordPress

Hello!

I work for a small family run pharmacy, and prior to my employment, the owner created a website using WordPress. He would like to update its look into something more professional, and while I’d be happy try my hand at it, I can’t access the account, hence the original coding!

He no longer has the information, and our current main work-email was apparently not used. Is there anyway to still access the account so we don’t lose his domain name by creating a new one?