from hashlib import blake2b

def hash_token(token, secret, salt):
    # first iteration
    h1 = blake2b(digest_size=32)
    h1.update((token + secret + salt).encode("utf-8"))
    hash1 = h1.digest()
    # second iteration
    h2 = blake2b(digest_size=32)
    h2.update(hash1)
    return h2.hexdigest().lower()

print(hash_token("my-test-token", "local_dev_secret_change_for_production_12345678901234567890", "testgroup"))