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Add an iFrame to a Content Editor

Add a Content editor webpart on a page From the Ribbon click on "Edit Source" in "Format Text". Add the following in the Source. <iframe [...]
Creating a forum in Sharepoint

Click the Settings gear icon and choose Add an App. Scroll down and click the Discussion Board App button. Type a name for the discussion [...]
REST API – jQuery – using List Items

Html file to add to the Content Web [...]

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