Rental Accounting Extract
This application has no web interface, so connecting is done from the computer it runs on. The operator runs the connect command, which opens Intuit's own authorization page in a browser. Consent is given there, on Intuit's site, by an administrator of the QuickBooks company being connected. Intuit then returns the result to a page on this site, which passes it back to the application on the operator's own computer.
python3 src/qbo_cli.py connect --env production
Each QuickBooks company is authorized separately, because an authorization applies to one company. Reconnecting works the same way: if an authorization expires or is revoked, the application stops, reports why, and the same command is run again.