If your W-2 does not include your exempt income, you do not need to report it or include the Form 8833 Treaty based exempt form to your tax return.
You only need to file Form 8833 if your company includes your exempt-income on tax forms like W-2 or 1099 to the IRS and you pay taxes on it. If your company did not report it to the IRS, and you qualify for the treaty benefit, you do not need to report the income.