Asking additional input while closing sprint

[Gantner NV]

Currently, if you close sprint with unresolved issue then user gets a pop-up about what to do with the unresolved issue. Here we also would like to ask for additional input e.g. Reason for not achieving goal - drop down with pre-filled reasons. 

Any idea how to achieve this? or anyone has achieved similar functionality?

[Jack]

This is not possible within Jira and I am unaware of any app that would allow you to achieve this. However that doesn’t mean one does not exist. You might check the marketplace for possible solutions. 
I should further note that this is precisely what retrospectives are for. So I encourage you to look at this functionality within Jira and leverage it to outline why certain stories were not completed

[Daniel Ebers]

Hi @Gantner NV

the approach using retrospectives was mentioned several times in past when it came to exact this requirement.
Adding to what Jack already said you could even use a Confluence page for a retrospective (if you already have Confluence).

You can link your sprints to the retrospectives easily.

Some more information on this idea can be found here:
https://support.atlassian.com/jira-software-cloud/docs/complete-a-sprint/#Other-tasks-to-complete-at-the-end-of-a-sprint

Regards,
Daniel