from typing import List


def computationalBasisList(qubitNum: int, sysLevel: int) -> List[str]:
    """
    Return a list of strings labeling eigenstates.
    For example, ``computationalBasisList(2, 3)`` will return:
    ``['00', '01', '02', '10', '11', '12', '20', '21', '22']``

    :param qubitNum: the number of qubits in the system
    :param sysLevel: the energy level of the qubits in the system
    :return: the list of strings labeling eigenstates
    """
    itemCount = sysLevel ** qubitNum
    strList = []
    for index in range(itemCount):
        bStr = ''
        for qu in range(qubitNum):
            bStr = f"{int(index / sysLevel ** qu) % sysLevel}{bStr}"
        strList.append(bStr)
    return strList