4 Jan 2022 Update:

Hi all! 

The rollout of ProForma (Forms for Jira) is now in progress and should be available to all customers in the next few weeks. 

ProForma will make it possible specify which choice value is required in a form.

Regards,

Simon Herd

Principal Product Manager, Jira Service Management

Summary

Currently, there is no way to set selected checkbox to be required for multiple check boxes field type to validate on issue transition.

Suggestion

Allow specifying of required check boxes in multiple check boxes field to be able to transition issues