1042 S

Hi, I got 1042 S and W2 from my company. I joined the company in January 2023, but the treaty for exemption (1042 S) only applied to September 2023 and after that I became an LPR. Now, the 1042 S form I received has only information about the September, though the exemption should be applied before that-- the amount in box 1 "Gross Income" of 1042 S should be much higher and the net taxable income should be lower in W2 form. I asked to my company about that and they told me I might not have signed the form before September, but I may be still claim for full treaty when I submit the tax return. Given this situation, how I can claim the full treaty and submit the tax return using Turbo? Thank you!