'Issue cannot be found when trying to add existing issue to epic

I am trying to add issue to epic. Here I found documentation: https://docs.gitlab.com/ee/user/group/epics/manage_epics.html#add-an-existing-issue-to-an-epic

but when I click Add and then Add existsing issue and paste issue link then it says: Issue cannot be found. I also tried putting #1

No idea why it doesn't work, is there any workaround for this?



Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source