If he has NET capital gains of $800, then he usually has no capital losses to carry over to 2023. His 2022 capital losses were all "used up" in arriving at the net $800 capital gain .
Furthermore, it is not necessary to file a tax return to preserve a capital loss carry forward, if a tax return is not otherwise required.
Sometimes the calculations are complicated and it may be worthwhile to prepare a tax return (even if you don't file it) to be sure the carry forward is accurately calculated. TurboTax can handle it and will prepare a "Capital loss carry forward worksheet" to show the how much of your capital loss that will be carried forward to the next year. But, in the case of a net capital gain, that is not usually needed.
