Since UpRaise is a Jira app it can be updated by Jira administrators only. Here is relevant documentation.
Step 1 - Click on Administration option at the top right corner of JIRA
Step 2 - Click on Add-ons option
Step 3 - Click on Manage add-on link
Step 4 - Search UpRaise in the list.
Step 5 - There will be a visual indication of whether an update is available. If it is, click on 'Update'.
