"How to I get it to charge the estate for the tax?"

The program is calculating zero tax because the distribution you made carries out DNI (distributable net income) to the beneficiaries and the estate gets a corresponding deduction (IDD - Income Distribution Deduction).

If you made a distribution in 2018 and are filing an income tax return for the estate for the 2018 tax year, then that the income earned by the estate is taxable to the beneficiaries and is reported on their K-1s.