It is possible to use your Google Slides, PowerPoint slides, and Keynote slides in Canva to use Canva's recording and design tools with those slides. The trick is to first make sure that your slides are in PowerPoint format. To do that download your Google Slides or Keynote slides as a PPTX file. Then you can upload that file to your Canva account where you can then use all of Canva's editing, design, and recording tools. Watch this video to see how that whole process works.
Applications for Education
Canva is one of my favorite tools for creating short video lessons with your existing slides. The process is less clunky than using a screen recording tool to capture your slides as you explain the key points on them. If you're a Google Slides, PowerPoint, or Keynote user who has ignored Canva's recording tool because you didn't want to have to recreate your slides, the method that I demonstrated in the video above is for you.