Ask HN: Contact Clients Through Viber Public Accounts for Businesses

Is it possible for a business with a distribution list of clients (phone numbers) to contact the client through Viber? Does the client has to start the conversation first(by following or sending a message to the public account). If yes, is it possible to send an invitation link to the client by some other channel to accept messages from the Viber public account? I would appreciate any info on the subject as it seems very confusing online if actively contacting the client through Viber is possible or not.