If your account allows direct transfers in ZEscrow, you first need to initiate a transfer from the subaccount to the master/operating account. Once the funds become available in the master/operating account (which is typically on the following business day), you can initiate an ACH or wire directly out of the master/operating account in the typical way through your financial institution. See further instructions on how to transfer funds here: How do I transfer money in and out of a subaccount?
If your account does not allow transfers in ZEscrow, you will first make the ACH or wire transaction on your bank account through your financial institution, and then the following business day you can assign the transaction to the correct subaccount in ZEscrow. See further instructions on how to assign transactions here: How do I assign transactions to a subaccount?