Toffoli gate implementation using Qiskit. The example prepares $\lvert 110\rangle$ (both controls $\lvert 1\rangle$, target $\lvert 0\rangle$) and applies the Toffoli gate, flipping the target to produce $\lvert 111\rangle$.

from qiskit import QuantumCircuit
from qiskit.quantum_info import Statevector
 
qc = QuantumCircuit(3)
qc.x(0)         # q0 = |1>
qc.x(1)         # q1 = |1>  => state is |110>
qc.ccx(0, 1, 2) # Toffoli: both controls |1>, flip target -> |111>
print(Statevector(qc))
# Statevector([0.+0.j, 0.+0.j, 0.+0.j, 0.+0.j, 0.+0.j, 0.+0.j, 0.+0.j, 1.+0.j], dims=(2, 2, 2))