The Creative Cloud Asset Browser allows you to view assets you have stored in Creative Cloud directly from a Jira issue. You can select an asset and attached to the Jira issue you are viewing.
Click the "Browse Creative Cloud" button.
If it is the first time you have used the feature, you will need to login with your Adobe ID and allow Jira to access your Creative Cloud Files. This only authorizes your access.
Other team members using Jira will not have access to browse your Creative Cloud Files and will need to authorize their own accounts if they wish to attach files. Of course, they will be able to view files you have attached to the issue.
Once you have authorized access, the Asset Browser will be displayed. Browse through your assets and choose the one you would like to attach. Hit "Open" and the access will be automatically uploaded to Jira.