Dear respected UPEA,.
Good day! Thank you for posting to Microsoft Community. We are happy to help you.
As per your description, that's correct in Word desktop client application, I'm afraid we cannot save as a PowerPoint file type.
To meet your requirement, if possible, you may upload your Word document into OneDrive online (cloud location) and open Word document into Word for web (online) app then click on File > Export > Export to PowerPoint presentation.
Or, the other way, you may start PowerPoint and import an outline from Word.
For example, create the document as an Outline using Heading Styles then save using the Rich Text Format (.rtf) file type. In PowerPoint you then can use Insert> Slides From Outline to import the .rtf content. Slides will be generated based on the Styles used. Here is article for your reference: Create a PowerPoint presentation from an outline
Appreciate your patience and understanding and thank you for your time and cooperation.
Sincerely,
Waqas Muhammad
