Jira Core: プロジェクトまたは課題キーの変更および更新
How to change an issue key? How to modify a project key? Is it possible to modify the format of a key?
クラウド / サーバー
You are able to modify the project key in the project's settings.
The format of the issue key itself e.g. AA-12345, can be modified in the self-hosted version of the Jira products, but not in the Cloud version.