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By linking a Jira issue in Salesforce, you can easily communicate the linking information from the Salesforce object to a Jira issue, keeping the Jira team within the loop.
Prerequisites
Your administrator has completed a project binding as well as entity and field mappings in Jira.
Your administrator has configured the Visualforce pages required for the Object.
Linking a Jira Issue
1. In a Salesforce object, click Associate/Create.
2. Click Create Jira Issue and the issue creation window will appear. 
3. Choose the desired Jira Project and Issue Type. All field and value mappings set by your administrator will be used to create the Jira issue.
4. Click on More Fields to Review to expand, you will see the Linked Issues textboxes.
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5. In the Linked Issues column, choose the type of association for the linked issues and type into the search bar for the issue that you want to link with. The dropdown will list issues based on what you type, click on the relevant issue. 
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6. Once the Linked Issues section has been filled, click on the Create button. 
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7. Upon successful creation, the "Issue created successfully" and the "Issue linked successfully" messages will be displayed.
Salesforce view:
Jira view: