I sold my employee stock options. Gains weren't reported in my W-2. I received a 1099-B with Net Proceeds as 1000$ and cost basis as 1500$. Net proceeds was calculated by subtracting the exercise costs of 1500$. What the broker reported as Net Proceeds was the Gains. In form 8949, if I fill Proceeds(d) with 1000$ and Cost Basis(e) with 1500$, then the Gain/loss (h) should be computed as d - e and has a loss of 500$. What adjustment code(f) and Adjustment Amount(g) should I use so that my gains are 1000$.

If the actual gain is $1,000, then adjust the proceeds and basis to report it as such.