When setting up a Live field, it's necessary to define a key:
This key ensures that a Connect field is updated in real time. Thus, as soon as a change is made in the datasource, it is immediately reflected in the Connect field.
To work properly, a key must meet the following two requirements:
- The key must be unique in the result set, otherwise there will be a duplication problem (see Problem of duplicates in the issue view);
- The key must not be changed in the datasource, otherwise the link between the Connect field and the datasource will be broken. Thus, the values previously selected in Jira will no longer be updated because their key will no longer be relevant (see Why is my Connect field not live?)
Regarding fields connected to the "Jira issues (JQL)" data source, the key is defined by default and corresponds to the issue ID, so you don't have to configure anything.