IE Mode for SharePoint
Microsoft Edge Browser, SharePoint, and Computer
Go to the URL edge://settings/defaultBrowser and set Allow sites to be reloaded in Internet Explorer mode to Allow.
2. When this setting is enabled, users can reload a site in IE mode by selecting Settings and more (the ellipses icon ...) > Reload in Internet Explorer mode. Users can also select Reload tab in Internet Explorer mode when they right-click on a tab or choose Open link in new Internet Explorer mode tab when they right-click on a link.
3. The Reload in Internet Explorer mode icon can be pinned to the toolbar. The toolbar button allows users to easily enter and exit IE mode and can be managed through the edge://settings/appearance URL.
4. You may also want to enable to Open the page in Internet Explorer mode next time.