Disable Report Export function
Navigate to [domain]/secure/admin/SiteDarkFeatures!default.jspa
On this page, add the “everit.jttp.disable.export” key
if it is added and enabled, users won’t be able to export reports and the exported csv, excel file will contain the following: "Export is disabled. Connect to JIRA Admin.".
If you want to allow export again, you just have to click on the disabled button on this page. No need to restart and stop the addon.