My stamp palette doesn't open in Acrobat

​@viera_2229 not sure if you are using the old classic Acrobat or new interface Acrobat. 

What exactly is happening with the Stamp Tool? Can you be a little more specific? You can’t see it?  Classic may be easier unless you are using AI. 

New Acrobat:
 

Enter ‘Stamp’ In the search field, in my case I have 6 options. Click on Open. 
 

Old Classic Acrobat (similar to the new interface):

Click on Tools beside the Home tab
 

Type in “Stamp’ in the search field, and either click on Add or Open