Unfortunately currently there is no way for changing default expiration period for password reset tokens.
There is a public facing feature request for this particular setting https://jira.atlassian.com/browse/CWD-4703. Please add your comment there as it would be really valuable for the Crowd team to understand your usecase and requirements.
For JSM June Challenge #2, share how your non-technical teams like HR, legal, marketing, finance, and beyond started using Jira Service Management! Tell us: Did they ask to start using it or...
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