What is the best way to use a secrets package, if previously I used a random package to generate unique_code in python?

i have this code for generate unique_code

using Random Package

import random

FullChar = 'CDHKPMQRVXY123456789'
total = 20
count = 7

for i in range(total):
        select = random.sample(FullChar, count)
        random.shuffle(select)
        unique_code = ''.join(select)
        print(entries)

I Tried Using Secrets Package

import random

FullChar = 'CDHKPMQRVXY123456789'
total = 20
count = 7

for i in range(total):
        select = random.sample(FullChar, count)
        select = secrets.SystemRandom.sample(FullChar, count)
        secrets.SystemRandom.shuffle(select)
        unique_code = ''.join(select)

Here I use random package to generate unique_code(import random), but I think this is the old way to generate unique_code with this package, I want to use secrets package to generate unique_code(import secrets). What is the best way to use a secret package(import secrets), if previously I used a random package to generate unique_code like the code I wrote earlier?

When I used Random Package it's Clear, but when i changes it to secret package it's showing error

    select = secrets.SystemRandom.sample(FullChar, count)
TypeError: sample() missing 1 required positional argument: 'k'

Thanks