There is no "extra step". The recipe proportions determine which type you get. Standard caramel is just chewy. If you add fat or milk proteins (insider tip: try milk powder), it becomes soft. The more fat, the softer.
Also, if you add liquid, it becomes liquid, and can be used as a sauce. The more liquid, the lower the viscosity.
Also, it is a continuum, there is no hard divide. You can't say that up to 30% cream it's a soft caramel, from 31% cream it's a sauce" or similar.
A recipe should tell you which kind it produces. The one you posted looks a lot like a sauce to me, although I don't have ratios handy to say for sure. I tried searching for it, but the only one I found was https://djoudjousemetauxfourneaux.wordpress.com/2015/11/02/sauce-caramel-maison-recette-de-christophe-michalak/, which has much less liquid and more butter, and is still supposed to be a sauce.