The existing community (guides.canvaslms.com) doesn't allow embedding.

Content is available for embedding at guides.instructure.com; however, this site will be discontinued at a future date. For referencing content, consider linking lessons from the community into your course content.

Many of our clients are using Canvas Guides to build their own training modules inside Canvas. We think this is a great idea since our product is changing so quickly. By embedding lessons in your course with iFrames, you can be sure that our most recent documentation is available to your learners. You can also link to the Guides in Modules.

Note: Some browsers such as Firefox and Chrome create security restrictions as noted in our general browsers lesson. If you visit a page in your Canvas course with an embedded iFrame that is linked to insecure content, you may see a shield icon in the browser address bar. You can choose to override the security restriction and display the content anyway by clicking the shield icon and then choosing Disable Protection on This Page or Load unsafe script.