Open your PowerPoint presentation
Go to the slide where you want to add the GIF
Click the Insert tab
Select Pictures
Choose This Device or Online Pictures
Locate and select the GIF file
Click Insert
Resize and position the GIF on the slide
Start the slideshow to play the GIF
Save the presentation
If the GIF does not animate, check that you are in Slide Show mode
If needed, use a newer version of PowerPoint for better GIF support