Add To Cart Button For Products

i need to set a add to cart button in the product section, which means i want to implement a add to cart button in all products which is shown in the product page . currently its showing a product detail button i need to change that to add to cart button.

i am attaching the product image for your reference

If a product has options, the "Select options" button id displayed

If a product does not have options, you will see the "Add to cart" button