There is no real need to prove your yeast, (if you know it's good).
If you want/need to prove your yeast, I would used the prescribed 2ozs. of water, and 1/2 tsp of sugar Water should be on the high side of 100 degrees F, I have seen recommendations of 115-120F
Once it gets a healthy scum on the top, proceed, subtracting the amount of sugar and water in the proofing cup from the general recipe.
test works for instant and active.
There is more available about this here on the King Arthur site.

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