text: How to: Export a Report (SharePoint Integrated Mode) | Microsoft Docs
  When you open a report from a SharePoint site, it opens in (HTML. To view a report in another application, you must export it.
  Exporting a report is an on-demand task that you perform when the report is open. However, if you want to always see a report in a particular format, create a subscription that delivers the report to a library or to a shared folder. In the subscription, you can specify output options so that the report is delivered in the preferred format to the location you specify. For more information, see How to: Create and Manage Subscriptions (SharePoint Integrated Mode).
  Not all formats work well for every report. In some cases, a report author might have designed a report with a particular format in mind. If you choose a different format, the appearance or behavior of the report might be different from what you expect. For example, for large reports that span multiple pages, you can expect to see different pagination when you export the report to another format. Similarly, reports that include visual content or interactive features (such as hyperlinks, or areas that expand and collapse) might not have those features in the exported report.