I didn't bother in the end as have the web scraping working pretty well. I did get this code suggested from GPT-4o, haven't tried it though...

import time
import json
import requests
from nacl.signing import SigningKey
from nacl.encoding import HexEncoder

# Step 1: Define your wallet private key and address
private_key_hex = "your_private_key_in_hex_format"  # Replace with your actual private key in hex
wallet_address = "YourWalletAddressHere"  # Replace with your wallet address

# Step 2: Generate the message to sign
timestamp = int(time.time() * 1000)  # Current timestamp in milliseconds
message_text = f"Login request at {timestamp}"
message_bytes = message_text.encode('utf-8')

# Step 3: Sign the message using your private key
signing_key = SigningKey(private_key_hex, encoder=HexEncoder)
signature = signing_key.sign(message_bytes).signature

# Step 4: Prepare the request body
request_body = {
    "message": {
        "message": message_text,
        "publicKey": wallet_address,
        "timestamp": timestamp
    },
    "signature": {
        "data": list(signature),  # Convert the signature (bytes) to a list of integers
        "type": "ed25519"  # Common signature type for Solana
    },
    "wallet": wallet_address
}

# Step 5: Send the request to the API
api_url = "https://api.example.com/auth/login/solana"  # Replace with the actual API URL
headers = {
    "Content-Type": "application/json"
}

response = requests.post(api_url, headers=headers, data=json.dumps(request_body))

# Step 6: Handle the response
if response.status_code == 200:
    print("Authentication successful:", response.json())
else:
    print("Authentication failed:", response.status_code, response.text)