Creating two list using three validation functions

Hello this is my first question and sorry I don't know how to phrase it,

I am trying to create a two list. The first list is for one set of codes (code1) and is validated in the VC function. The second function (VC) is to validate the second list. Both functions work well in validating the numbers. However in the third function (add_validations). In that function I want to repeat VC and VQ until the user either types in END or either of the functions return False. When true I want the inputs to be appended into the two separate lists. However, the third function not only does not append any of the list it does not identify/run either of the two functions and comes up with:

TypeError: int() argument must be a string, a bytes-like object or a number, not 'NoneType'

And I'm sorry I didn't know which code to add so I added everything (delete if not allowed sorry):

Code:

def add_validations():
    code1 = []
    code2 = []
    VC()
    VQ()
    while True:
        record = []
        i = VC()
        q = VQ()
        if i != "END":
            VQ()
            VC()
            code1.append(int(i))
            code2.append(int(q)) 
        elif VC == True and VQ() == True:
            VQ()
            VC()
            code1.append(int(i))
            code2.append(int(q)) 
        elif VC == False and VQ() == True:
            print("Invalid code")
        else: 
            print("Invalid quantity")
    return code1,code2
        
def VC():
    i = input("What is the item code \n")
    minimum = 0
    maximum = 39
    if i == "END":
        i = "END"
        return  showRecord()           
    elif int(i) > minimum and int(i) <= maximum:
        return int(i)
        True
    else:
        False
    
def VQ():
    q = input("What quanity \n")
    minimum = 0
    maximum = 49
    if q == "END":
        isValidCode = "END"
        return  showRecord()
    elif int(q) > minimum and int(q) <= maximum:
        True
    else:
        False