if the employer made the HSA contribution out of its own funds and/or deductions from your paychecks, the employer must report those contributions on 12W. contact your employer for a corrected W-2. that amount would flow to form 8889 which you would need to complete. without a corrected W-2 you can expect a letter from the IRS. any amount taken from your paychecks to fund the HSA is supposed to reduce taxable wages in box 1 so you might want to check to see if box 1 is correct. other items like your contributions to an employer-sponsored retirement plan can also reduce box 1 wages.
