Entering input to a website and generating output for all files in folder using Google Chrome [MacOS; Terminal]

Okay here is what I came up with. Make sure you have wget installed. It takes in the HSA number as a first input and the color codes file as a second. It then generates a color codes string to build the cURL. The result of the cURL is a redirect to the correct URL. This then pulls the HTML and cuts out the temporary file that gets generated when you navigate to this page. It then uses wget to get the png.

After saving this to downloadhsa.sh file and then chmod +x, you would run with ./downloadhsa.sh hsa00010 colorcodes.txt

#!/bin/sh
HSA=$1
COLOR_CODES_FILE=$2

if [[ ${HSA} == "" ]]; then
  echo "No HSA number given"
  exit 1
fi

if [[ ${COLOR_CODES_FILE} == "" ]]; then
  echo "No color codes file given"
  exit 1
fi
COLOR_CODES=$''
i=0
while IFS=$'\n' read -r line; do
  ((i >= 1 )) && COLOR_CODES+=$'\r\n'$line
  ((i++))
done <${COLOR_CODES_FILE}

printf ${COLOR_CODES}
echo "Generating file for ${HSA}..."
BASE_URL="https://www.genome.jp"
IMAGE_URL=$(curl -L 'https://www.genome.jp/kegg-bin/mcolor_pathway' \
  -H 'Connection: keep-alive' \
  -H 'Cache-Control: max-age=0' \
  -H 'sec-ch-ua: " Not;A Brand";v="99", "Google Chrome";v="91", "Chromium";v="91"' \
  -H 'sec-ch-ua-mobile: ?0' \
  -H 'Origin: https://www.genome.jp' \
  -H 'Upgrade-Insecure-Requests: 1' \
  -H 'DNT: 1' \
  -H 'Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryV72KHjGaYHrBOToa' \
  -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.114 Safari/537.36' \
  -H 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9' \
  -H 'Sec-Fetch-Site: same-origin' \
  -H 'Sec-Fetch-Mode: navigate' \
  -H 'Sec-Fetch-User: ?1' \
  -H 'Sec-Fetch-Dest: document' \
  -H 'Referer: https://www.genome.jp/kegg/tool/map_pathway3.html' \
  -H 'Accept-Language: en-US,en;q=0.9' \
  --data-raw $'------WebKitFormBoundaryV72KHjGaYHrBOToa\r\nContent-Disposition: form-data; name="map"\r\n\r\n'"${HSA}"$'\r\n------WebKitFormBoundaryV72KHjGaYHrBOToa\r\nContent-Disposition: form-data; name="unclassified"\r\n\r\n#hsa CLP/CMP Blast_phase All\r\n'"${COLOR_CODES}"$'\r\n------WebKitFormBoundaryV72KHjGaYHrBOToa\r\nContent-Disposition: form-data; name="s_sample"\r\n\r\n\r\n------WebKitFormBoundaryV72KHjGaYHrBOToa\r\nContent-Disposition: form-data; name="mapping_list"; filename=""\r\nContent-Type: application/octet-stream\r\n\r\n\r\n------WebKitFormBoundaryV72KHjGaYHrBOToa\r\nContent-Disposition: form-data; name="mode"\r\n\r\ncolor\r\n------WebKitFormBoundaryV72KHjGaYHrBOToa\r\nContent-Disposition: form-data; name="numericalType"\r\n\r\nmm\r\n------WebKitFormBoundaryV72KHjGaYHrBOToa\r\nContent-Disposition: form-data; name="minColor"\r\n\r\n#ffff00\r\n------WebKitFormBoundaryV72KHjGaYHrBOToa\r\nContent-Disposition: form-data; name="maxColor"\r\n\r\n#ff0000\r\n------WebKitFormBoundaryV72KHjGaYHrBOToa\r\nContent-Disposition: form-data; name="negativeColor"\r\n\r\n#00ff00\r\n------WebKitFormBoundaryV72KHjGaYHrBOToa\r\nContent-Disposition: form-data; name="zeroColor"\r\n\r\n#ffff00\r\n------WebKitFormBoundaryV72KHjGaYHrBOToa\r\nContent-Disposition: form-data; name="positiveColor"\r\n\r\n#ff0000\r\n------WebKitFormBoundaryV72KHjGaYHrBOToa--\r\n' \
  --compressed | grep "id=\"pathwayimage\"" | cut -d " " -f 2 | cut -d "\"" -f 2)

echo "Downloading image ${HSA} from ${BASE_URL}${IMAGE_URL}..."
if [[ ${IMAGE_URL} == "" ]]; then
  echo "No URL returned for which to fech an image"
  exit 1
fi

wget ${BASE_URL}${IMAGE_URL}