you'll need to use a tool like vanitygen or another brute-forcing tool. Below is an example script using Python to achieve this. Please note that brute-forcing a Bitcoin key is computationally expensive and may take an impractical amount of time, depending on your hardware and the range you are scanning.

Here's the Termux script:

Type command nano to save this file 

                       


#!/data/data/com.termux/files/usr/bin/bash


# Install necessary packages

pkg update && pkg upgrade -y

pkg install python git -y


# Clone a BTC key scanner repo (assuming a tool like vanitygen)

git clone https://github.com/samr7/vanitygen.git

cd vanitygen


# Compile the vanitygen tool

make


# Run the key scan within the specified range

./vanitygen -s 20000000000000000:3ffffffffffffffff -o output.txt 13zb1hQbWVsc2S7ZTZnP2G4undNNpdh5so


# Print out the results

cat output.txt

Save the Script:

Save the above script as btc_puzzle_scanner.sh and give it execute permission:

bash
chmod +x btc_puzzle_scanner.sh

Then run the script:

bash
./btc_puzzle_scanner.sh

Caution: Using brute-force methods on large key ranges can be extremely slow and resource-intensive, and is unlikely to succeed unless you have significant computational power or the puzzle is specifically designed to be solvable. Use this script responsibly and be aware of the ethical and legal implications.