Basically, three things oblige a company to do so:
The dispensing resolution ceases to be in force. For example, the members adopt a new resolution to revoke the dispensation.
A member requests an AGM within 14 days before the last day of the 6th month after the Financial Year End (FYE).
If a member or an auditor requests an AGM within 14 days after the company sent out the financial statements.
In these three cases, the company is obliged to hold an offline AGM within 6 months after the FYE.