the policy must be in the name of the S-corp or your name. if your name then the S-Corp should either pay the premiums directly or reimburse you if you pay. health insurance is regarded as a fringe benefit so the amount, according to IRS instructions, for a 2% or more shareholder must be included on line 7 or 8. line 7 if you are an officer. that would be the case if you are the only employee.
at year-end, the premium amounts must be included on your w-2 as wages. (it's also reported in box 14 of the w-2) then when you enter the k-1 there is a question under other situations that asks about health insurance. this results in a deduction for health insurance on schedule 1 line 17. note that this deduction is limited to the amount of medicare wages on your w-2