You can reuse an already created Test scenarios/Test cases and associate it to JIRA Issues.
Example :
Step 1. Open a Story where you wish to associate the same Test scenario/Test cases >> Go to 'Test Cases/Acceptance Criteria' section
Step 2. Search for the Test scenario/Test Case by "Summary" OR "JIRA ID" with other filters and associate it with the story.
Here is the link to help documentation.