If the gain is passed to the beneficiary, the withholding goes to the individual and can’t go on K01
This is from our Analysis and Explanation of California Taxes
Passing withholding to beneficiary
When property is sold by an irrevocable (nongrantor) trust, the escrow company completes a Form 593 listing the name of the irrevocable trust as the seller. The trustee will receive a Form 593 in the name of the trust. If there was withholding on the sale, the trust must then file an FTB Form 592, Resident and Nonresident Withholding Statement, to transfer the withholding to the beneficiary and provide the beneficiary with a FTB Form 592-B, Resident and Nonresident Withholding Tax Statement.
Unfortunately, the current process does not allow the trust to pass through the withholding using the state withholding line on Schedule K-1.