Add to cart or buy button on product page missing

I searched the topics but can’t find the answer I’m looking for. There’s no add to cart or buy button on my product pages. Do I need to create this? Or can someone give me the link to the answer? Thanks.

Hi,

May be there is any settings/configuration issue in the product settings.
Please contact your purchased theme/item author, theme/item author will assist you.

How to contact an author to get support or for any technical query:

Thanks