You have to do 100 conversion correctly.
For example:
> convert bytearray to hexdigest: [129, 141, 112, 176, 251, 106, 160, 102] @@@@@
>
> convert integer to bytearray: 1639309969325418938 @@@@@
>
> convert bytearray to integer: [55, 107, 189, 150, 85, 213, 147, 94] @@@@@
>
> ...

The solution was scripted with python. The idea is to use pwntools for connect to remote host, parse the input using splitting and replace methods for get base_a, base_b and the value. When we have all the these values we can convert first to bytes and then to base_b request.

```
import binascii
from pwn import *

def parse_message(message):
try:
message = message.replace(b"convert", b"").strip()
message = message.replace(b" @@@@@", b"").strip()
base_a = message.split(b"to")[0].replace(b"convert", b"").strip()
base_b = message.split(b"to")[1].split(b":")[0].strip()
pivot = (f"{base_b.decode()}:").encode()
value = message.split(pivot)[-1].strip()
return base_a.decode(), base_b.decode(), value
except Exception as e:
print(f"Exception raised: {e} with message: {message}")

if __name__ == "__main__":

conn = remote('challenges.ctfd.io', 30008)
for i in range(0, 120):
for j in range(0, 2):
print(conn.recvline())

line = conn.recvline()
base_a, base_b, value = parse_message(line)
print(line)
print(f" Parsed to: from **{base_a}** to **{base_b}** ===> ", value)

response = None
#1 - Convert start types in byte. stop
if base_a == "bytearray":
bytes_value = bytes( bytearray ( eval ( value ) ) )
elif base_a == "hexdigest":
bytes_value = bytes.fromhex( value.decode() ) # TypeError: fromhex() argument must be str, not bytes
elif base_a == "string":
bytes_value = value.strip() # (?)
elif base_a == "integer":
bytes_value = (int(value)).to_bytes(8, 'big')

#2 - Convert byte from what you want.
if base_b == "bytearray":
response = str( list( bytearray(bytes_value) ) )
elif base_b == "hexdigest":
response = bytes_value.hex()
elif base_b == "string":
response = bytes_value.strip()
elif base_b == "integer":
response = str( int.from_bytes(bytes_value, byteorder='big', signed=False) )

if response is not None:
print(b"Going to send response ===> ", response)
conn.send(response)
conn.send(b"\n")
print(b"Response from challenge: " + conn.recvline())
print(conn.recvline())
print(f"\n {i+1} ===================================\n")
else:
print("No response was provided")
```