Definitely disclose as soon as you possibly can - basically as part of your first hellos. If you mostly have silent blocks, you’ll have to explain this also bc most ppl don’t realize your oddly timed pauses are actually part of your stutter. Please don’t apologize. just be brief, factual and maybe add in some humor or a way its a benefit as en employee. (Many SLPs who specialize in dusfluency also suggest that you do the above in as many new speaking situations as possible)