Since version 2.3, anonymous users can use Issue Forms for Confluence to create issues in Jira (within Confluence).
The page can look like this.
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- Within Jira, you must ensure that Anonymous users can create Issues.
- Anonymous access to Confluence and the corresponding spaces must be active
- Select "Edit" on the page with the "Issue Forms - create form"-macro
- Add the "Issue Forms - captcha"-macro
- Save/Publish the page
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