There are several instances where this might be necessary, as sometimes the main page notification bar disappears. Since the license key can be entered in that bar, the following trick might be needed.
What you also need to know is that the license check is done by a scheduled task, but it is a hidden cron job. So, even if we are in developer mode, it won't be available. Therefore, we can't manage its settings or rerun it, for example, to make the notification for entering the key reappear or even to disable it if needed. (It runs weekly by default).
For the currently relevant version 18, we can proceed as follows:
Open our Odoo instance with the following URL to enable developer mode:
/odoo?debug=1
How to change Odoo enterprise database expiration date
update ir_config_parameter set value=’2026–03–30 00:00:00' where id=22;
update ir_config_parameter set value=’M21032924750231' where id=70;