Parameterizing the input wavefunciton in qiskit VQE

I wonder how I can plug in my own customized wavefunction form while using VQE in qiskit. Thanks in advance!

You can parameterized your QuantumCircuit before plugging it into VQE. For example

from qiskit.algorithms import VQE
from qiskit.circuit.library import EfficientSU2

# the rotation gates are chosen randomly, so we set a seed for reproducibility
num_qubits = 4
ansatz = EfficientSU2(num_qubits, reps=1, entanglement='linear', insert_barriers=True)

vqe = VQE(ansatz=ansatz, ... )

You can see a full example here: qiskit.org/documentation/partners/qiskit_runtime/tutorials/vqe.html