How to send referrals or advertisements to the chat of subscribers of a group (not mine) of telegrams?

Question

Internet advertising

There are many chats that display tens of thousands of subscribers with their nicknames, IDs and sometimes phone numbers. How to do a mailing in a personal to such users of your advertising or referrals (let's say)?
ps
This is not about aggressive advertising and something forbidden!

Answer 1

Request user approval to receive the newsletter. Buy advertising-announcement of your newsletter in these chats. Subscribe to your channel = approval.