who owns ET? I'm betting it's in a retirement plan because form 8868 is an extension only for tax-exempt entities such as a retirement plan not your personal return. if I'm correct the k-1 does not get reported on your 1040. look at 20V on the k-1. That's the partnership's Unrelated Business Taxable Income (UBTI). if it's more than $1000 (also any other k-1's that have an amount for 20V) your retirement plan was supposed to file form 990-T and pay the UBIT (Unrelated Business Income Tax).
since it would seem the retirement plan is at Schwab, usually the trustee does the filing. However, they don't get the k-1. If filing of the 990-T is required contact Schwab for the procedure.
anyway, it's too late to file the extension since the 990-T, if required, was due, 4/15/2024, (the 15day of the 4th month after the year end of the retirement plan which would normally be 12/31/2023).
if your UBTI is under $1000 no filing is required.
