I need the help of a Telethon api expert to solve this issue.

Here is the working code:

  from telethon import TelegramClient, events, sync

  api_id = 123
  api_hash = 'abc123456'

  client = TelegramClient('ok', api_id, api_hash)
  client.start()

  channel_username = 'channelusername'

  for message in client.get_messages(channel_username, limit=5):
  print(message.message)

The primary objective is to find the channel username from this link format:

eg.