Maria F. answered 22d
Computer Science Tutor with 6+ Years of Experience | Java| C++|Python
This usually happens because the footer is not applied to all slides or the layout doesn’t support it.
Go to Insert > Header & Footer, tick Footer, add text, then click Apply to All.
If it still doesn’t show, go to View > Slide Master and check each layout. Make sure the footer box is visible and not hidden or moved off slide.
Also check your slide layout. Some layouts don’t show footers, so switch to a basic layout like Title and Content.