The application works fine on my PC. No timeouts. When I turned it off to move it to my server, at first after logging into the session with phone number, password, and login code, this error appeared:
telethon.errors.rpcerrorlist.FloodWaitError: A wait of 31387 seconds is required (caused by ResolveUsernameRequest)
on line
client.get_messages(channel_name, ids=141)
I waited way longer than the ~8+ hours.
My PC program was working fine. I again stopped it and opened the same script on my server.
Now the wait is doubled:
telethon.errors.rpcerrorlist.FloodWaitError: A wait of 67203 seconds is required (caused by ResolveUsernameRequest)
on same line. Unusable.
This is MY OWN channel owned by the very account I sign in to that I'm getting the message from...
Your question title mentions you "can't login", but your question body seems to indicate otherwise. I will assume your problem is what's described in the question's body.
Telethon will use the .session file as a cache, containing, among other things, usernames and their corresponding id and access_hash. Both of these values are required to use a chat as a parameter for the API requests.
If the username is not in cache, the library will need to fetch it first. This fetching has a high flood wait, and there's no way to bypass that.
The correct approach here would be to:
print(await client.get_input_entity(channel_name))
once, and then hardcode the output in your script, like so:
from telethon import types
CHANNEL = types.InputPeerChannel(channel_id=..., access_hash=...)
(You can use a different mechanism to store it persistently. Hardcoding it is just the simplest way to do it.)
And then you can use CHANNEL instead of channel_name.