Use the token SamDoesArt to trigger the effect. It should work anywhere in the prompt. I usually put it right at the beginning of the prompt, which has a mildly different effect than putting it at the end of the prompt. Up to you though to do some test and find where is the prompt is best for your personal tastes. I don't recommend putting the word style directly after the keyword like most custom models do. On this model it will cause unpredictable, wierd results that probably aren't what you truly want. The effect of a comma after SamDoesArt or no comma is difficult to determine.
"SamDoesArt, portrait of a pretty girl" "SamDoesArt, a man working in a factory, manly, machines" "SamDoesArt, an african lion, mane, magestic
You get the idea. A much more thorough and much more visual guide to the model can be seen here: https://www.reddit.com/r/StableDiffusion/comments/za1d7p/samdoesart_v3_intended_to_improve_both_human/
Still don't like this website and don't understand why it is so user unfriendly...