poetry self update doesn't work with private repository

[theFireProject]

How can you get the poetry self update command to use a private package repository?

I get this error when running poetry self update because I cannot access official PyPI:

HTTPSConnectionPool(host='pypi.org', port=443): Max retries exceeded with url: /simple/poetry/ (Caused by NewConnectionError('<urllib3.connection.HTTPSConnection object at 0x000001F123734650>: Failed to establish a new connection:
 [WinError 10061] Es konnte keine Verbindung hergestellt werden, da der Zielcomputer die Verbindung verweigerte'))