use recaptcha service on just first tier

sorry if the answer is already on here, but ive searched & did not find the answer, but how do you just select to use the recaptcha service (i.e. deathbycaptcha) on just the first (top) tier ?
ive looked in the “captcha” admin where you add the captcha service & there is nothing there.
i can only see it applies universally to everything.
i have gsa captcha breaker already – then first tier to go to deathbycaptcha
but i want lower tiers to be gsa captcha breaker only