Update certificates via API

Question

I have my certificates in a folder and I'm looking for a script that will update them when there is a change so that waf will continue working without manual intervention. 
 I have very little experience scripting, I can read and understand more or less. But anyone has something like this working? with the help of AI I have manage to get this but it need some fixes to make it work. 
 Anyone can help? 
 #!/bin/bash

# Define variables
CERT_FOLDER="/path/to/your/certificate/folder"
SOPHOS_API_URL="https://your-sophos-firewall.com:4444/webconsole/APIController"
SOPHOS_USERNAME="your-username"
SOPHOS_PASSWORD="your-password"
CERT_NAME="subzerocloud"
NEW_CERT_NAME="new_subzerocloud_certificate"

# Function to authenticate and get the API token
get_api_token() {
 local LOGIN_DATA=$(jq -n \
 --arg username "$SOPHOS_USERNAME" \
 --arg password "$SOPHOS_PASSWORD" \
 '{"username": $username, "password": $password}')
 
 local RESPONSE=$(curl -s -k -X POST "$SOPHOS_API_URL/login" -d "$LOGIN_DATA")
 echo "$RESPONSE" | jq -r '.data.token'
}

# Function to read certificate files
read_certificate_files() {
 PEM_CONTENT=$(cat "$CERT_FOLDER/certificate.pem" | base64 -w 0)
 KEY_CONTENT=$(cat "$CERT_FOLDER/private.key" | base64 -w 0)
}

# Function to check if the certificate exists
check_certificate_exists() {
 local TOKEN=$1
 local RESPONSE=$(curl -s -k -X GET "$SOPHOS_API_URL/get/certificate/certificate" \
 -H "Authorization: Bearer $TOKEN")
 
 echo "$RESPONSE" | jq -e ".data[] | select(.name == \"$CERT_NAME\")" > /dev/null
}

# Function to create a new certificate
create_new_certificate() {
 local TOKEN=$1
 local JSON_PAYLOAD=$(jq -n \
 --arg name "$NEW_CERT_NAME" \
 --arg cert "$PEM_CONTENT" \
 --arg key "$KEY_CONTENT" \
 '{"name": $name, "certificate": $cert, "privateKey": $key, "type": "certificate"}')

local RESPONSE=$(curl -s -k -X POST "$SOPHOS_API_URL/set/certificate/certificate" \
 -H "Authorization: Bearer $TOKEN" \
 -H "Content-Type: application/json" \
 -d "$JSON_PAYLOAD")

echo "Response from POST /set/certificate/certificate: $RESPONSE"

if [[ $(echo "$RESPONSE" | jq -r '.status.code') == "200" ]]; then
 echo "New certificate created successfully: $NEW_CERT_NAME"
 else
 echo "Error creating new certificate: $(echo "$RESPONSE" | jq -r '.status.message')"
 exit 1
 fi
}

# Function to update an existing certificate
update_sophos_certificate() {
 local TOKEN=$1
 local JSON_PAYLOAD=$(jq -n \
 --arg name "$CERT_NAME" \
 --arg cert "$PEM_CONTENT" \
 --arg key "$KEY_CONTENT" \
 '{"name": $name, "certificate": $cert, "privateKey": $key, "type": "certificate"}')

local RESPONSE=$(curl -s -k -X PUT "$SOPHOS_API_URL/set/certificate/certificate" \
 -H "Authorization: Bearer $TOKEN" \
 -H "Content-Type: application/json" \
 -d "$JSON_PAYLOAD")

echo "Response from PUT /set/certificate/certificate: $RESPONSE"

if [[ $(echo "$RESPONSE" | jq -r '.status.code') == "200" ]]; then
 echo "Certificate updated successfully"
 else
 echo "Error updating certificate: $(echo "$RESPONSE" | jq -r '.status.message')"
 exit 1
 fi
}

# Main function
main() {
 echo "Starting certificate update/creation process..."
 
 # Authenticate and get the API token
 API_TOKEN=$(get_api_token)
 if [ -z "$API_TOKEN" ]; then
 echo "Authentication failed. Please check your credentials."
 exit 1
 fi

# Read the contents of the certificate files
 read_certificate_files

# Check if the certificate already exists
 if check_certificate_exists "$API_TOKEN"; then
 echo "Certificate $CERT_NAME exists. Updating..."
 update_sophos_certificate "$API_TOKEN"
 else
 echo "Certificate $CERT_NAME does not exist. Creating a new one..."
 create_new_certificate "$API_TOKEN"
 fi

echo "Process completed."
}

# Execute the main function
main