Insert a tab character in PowerPoint 2016
Keynote is accepting tab directly. Is much easier to use than any version of PowerPoint and is able to output PowerPoint format which is readable with many PowerPoint versions.

My personnal experience is that Keynote is providing a more compatible PowerPoint than any version of PowerPoint, and is also much user friendly.

Actually I don't use PowerPoint for quality and security reasons.

Then this part of advice is untested!

I suggest you to try:

ctrl+Q, tab

or:

ctrl+V, tab