A modified script from https://github.com/tpill90/steam-lancache-prefill/blob/master/scripts/update.sh to install & update BattleNetPrefill

install_battlenet.sh

#!/bin/bash
Cyan='\033[0;36m'
RED='\033[0;31m'
Yellow='\033[0;33m'
NC='\033[0m' # No Color

cd /data

# make BattleNet dir
if [ -d "BattleNet" ] 
then
    echo "Directory `BattleNet` exists." 
else
    echo "Creating BattleNet dir"
	mkdir BattleNet
fi

cd BattleNet

# Checking for required software
if ! [ -x "$(command -v curl)" ]; then
  echo -e "${RED}Required software curl is not installed.${NC}" >&2
  exit 1
fi
if ! [ -x "$(command -v jq)" ]; then
  echo -e "${RED}Required software jq is not installed.${NC}" >&2
  exit 1
fi
if ! [ -x "$(command -v unzip)" ]; then
  echo -e "${RED}Required software unzip is not installed.${NC}" >&2
  exit 1
fi

# Getting latest version tag
echo -e "${Yellow} Checking for latest version ${NC}"
VERSION_API_BATTLENET="https://api.github.com/repos/tpill90/battlenet-lancache-prefill/releases"
LATEST_TAG_BATTLENET=$(curl -s $VERSION_API_BATTLENET | jq -r '.[0].tag_name' | cut -c 2-)

if [ -z "${LATEST_TAG_BATTLENET}" ]; then
    echo -e " ${RED}Something went wrong, unable to get latest version!${NC}"
    exit 1
fi
echo -e " Found latest version : ${Cyan} ${LATEST_TAG_BATTLENET} ${NC}"

# Downloading latest version
echo -e "${Yellow} Downloading... ${NC}"
DOWNLOAD_URL_BATTLENET="https://github.com/tpill90/battlenet-lancache-prefill/releases/download/v${LATEST_TAG_BATTLENET}/BattleNetPrefill-${LATEST_TAG_BATTLENET}-linux-x64.zip"
wget -q -nc --show-progress --progress=bar:force:noscroll $DOWNLOAD_URL_BATTLENET

# Unzip
echo -e "${Yellow} Unzipping... ${NC}"
unzip -q -j -o BattleNetPrefill-${LATEST_TAG_BATTLENET}-linux-x64.zip

# Cleanup
rm BattleNetPrefill-${LATEST_TAG_BATTLENET}-linux-x64.zip
chmod +x BattleNetPrefill

if [ -f update.sh ] 
then
    chmod +x update.sh
else
    echo update file doesnt exists.
fi

echo -e " ${Cyan} Complete! ${NC}"

I suggest using the following command instead of unzip:
unzip(){ python3-c "from zipfile import PyZipFile; PyZipFile( '''$1''' ).extractall()"; }
Because unzip is not available in many places by default