How to show the checkbox  on the cart page?

It will show the T&C checkbox automatically on your cart page & cart drawer , and on the Buy Now button once you active the app.

How can  i add more than one link  to the terms  and conditions text?

Go to the app checkbox settings and select the text with link option  then, it will show the two textbox to add text and links , you can write your text and links.

How to  add the terms and conditions  in specific countries?

Go to the app appeareance tab and check the show the checkbox for certain countries only checkbox and choose the countries which you want to show the checkbox.