When clicking on the various components you will see a “buy now” link in the bottom-right corner. If you click this link, you will be redirected to the website where you can buy the specific product that we recommend.
In addition, in the BoM (bill of materials) in the circuito reply, notice that the names of the components are clickable
This too will lead you to the website where you can buy the components.
You can, of course, purchase the components from other distributors\manufacturers, however, you need to make sure that these components are similar to the ones on circuito, or else the circuit may not work properly.