To do this, simply open Keynote in Mac and then click "File" on the taskbar.
In the drop-down menu, click "Open".
On our Finder, find the PowerPoint presentation you want to open, select it and click "Open".
The PowerPoint file will open in Keynote. Most likely, you will see some warnings. For example, as shown in the image below, the source files may be missing for some fonts that Keynote does not support. Click on the word "Show" to see more information.
A dialog box appears that will allow you to resolve any issues.
In our example, the fonts that have the exclamation mark next to them need to be replaced. In such cases, click on the arrows to the right of each font (or other element) to replace.
When you are satisfied with your options, click on "Replace Fonts".
This replacement could change some formatting within the presentation, so it's a good idea to do a check to see that everything is OK.
To convert a PPTX file to a KEY file, save it by clicking on “FileOn the taskbar and then clicking "Save".
Give your presentation a name, choose where you want to save it, and then click "Save".