Not able to figure out how private hex keys and public hex keys should be used from WIF private key (52 character long)

[shbhmbnsl1]

This is a follow up issue of #118

Here I was facing issue in sending litecoin using simple spend api to p2wpkh style litecoin addresses because it seems to be a problem in simple spend api of blockcypher that it cannot let us send funds to those kind of wallets. (Has there been any fix for it?)

Regardless, I tried the another approach of creating unsigned transaction, then signing the transaction but I am not able to understand what privatekeyhex and publickey hex values should be for the make_tx_signatures function call? To begin with, I have a WIF private key for my litecoin wallet (this is 52 character long key) and a sender litecoin address.

A working example should be good.

Here is my code

import bitcoin
from blockcypher import create_unsigned_tx
from blockcypher import make_tx_signatures
from blockcypher import broadcast_signed_transaction
import base58
from coincurve import PrivateKey

API_KEY = 'my_api_key'

def priv_to_pub(priv_key_hex):
    private_key = PrivateKey.from_hex(priv_key_hex)
    return private_key.public_key.format().hex()

private_key_WIF = 'my_private_key_wif_52_character_long'
first_encode = base58.b58decode(private_key_WIF)

# Not sure how to get the hex from the 52 character private key, this works for 51 but not for 52
hexStr = first_encode.hex()
hexStr = hexStr[:-8]
hexStr = hexStr[2:]

inputs = [{'address': 'LU53RhwffkxLTgby5nE3YJ9LZotnhthwgV'}, ]
outputs = [{'address': 'ltc1q535aq2q3k6rm5atamgesqd49zu7ckmlj45lmpp', 'value': 1000000}]
unsigned_tx = create_unsigned_tx(inputs=inputs, outputs=outputs, coin_symbol='ltc', api_key=API_KEY)

pubkey_list = [priv_to_pub(hexStr)]
privkey_list = [hexStr]

tx_signatures = make_tx_signatures(txs_to_sign=unsigned_tx['tosign'], privkey_list=privkey_list, pubkey_list=pubkey_list)

print(tx_signatures)

print(broadcast_signed_transaction(unsigned_tx=unsigned_tx, signatures=tx_signatures, pubkeys=pubkey_list, api_key=API_KEY))

I get this error 'ValueError: Secret scalar must be greater than 0 and less than 115792089237316195423570985008687907852837564279074904382605163141518161494337.
' when converting private key to public key.

Please suggest some solution to this - I am stuck for a long time.