To be able to find the id you must be a previous participant in channel, group or one of the conversation.
Goto channel, group or conversation you want get id
Click right mouse a message in channel, group or conversation
Select Forward to and find bot @GetDetail_Bot
Forward message Chosen to bot https://t.me/GetDetail_Bot
At here will have all info of channel, group or conversation
Copy Origin Chat ID is -1001447685810 and remove -100. ID FINAL is 1447685810.
Copy it to App Autoforward Telegram
Goto group have Topics
Click right click select Copy Post Link from Message
We will receive link same like "https://t.me/c/1656164752/2/7553"
Copy Topic_ID is path near the end, corresponding = 2