Caramel with their 3 stages (liquid, soft, chewy): What is the key difference when cooking?
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.