Hi @Norhasnah bt Mohd Nordin ,
You can refer to this support article:
https://support.microsoft.com/en-us/office/create-professional-slide-layouts-with-powerpoint-designer-53c77d7b-dc40-45c2-b684-81415eac0617
And you can find the information: This is a subscriber-only, Microsoft 365 feature.
Hope the information is helpful.
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