Did not have enough yeast for my bread recipe (bread machine)?

Sorry, the brewers yeast will not help your bread rise or anything though I doubt that 3 teaspoons will ruin your bread either. Brewer's yeast is a kind of yeast that is a by-product of brewing beer and has no leavening qualities because it is inactive yeast.

If you use less yeast than required the dough will still rise but it will take longer and the bread may be less sweet as the yeast uses up the sugars in the wheat. I prefer my bread this way and regularly use 1/4 tsp or less instant yeast to a large loaf of bread.

You just have to go by look and not time. The first proving will be done when the dough has doubled in volume. Knock it back and shape according to instructions. The second rising may take a little longer too. The oven time will be exactly the same.

Brewers yeast is different, so you won't get the big rise from it. But 3 tsp of yeast should be ok.

Brewers yeast is slower acting.

Just let the dough proof longer.

no that will not help.. Brewers yeast is dead.

Your bread will take longer to rise -- that is all...