Install PrestaShop

Prerequisites

Before starting the installation, make sure that:

• You are running PrestaShop 1.6 or later — every version from 1.6 through the latest 8.x and 9.x releases is supported (keeping your store up to date is recommended)
• You have access to the administrator back office
• Your site is accessible over HTTPS

Generate an API access key in PrestaShop

To use PrestaShop's Webservice API with Order Invoicer, you must first enable the feature and then generate a secure access key.

1. Enable the Webservice

1. Access the PrestaShop back office with your administrator credentials
2. Navigate to Advanced Parameters > Webservice (labelled Web service on PrestaShop 1.6)
3. Enable the Enable PrestaShop's webservice option by selecting "Yes"
4. Click Save to apply the changes

Important: Enabling the webservice is required for Order Invoicer to retrieve your orders and customer data.

2. Create a secure access key

1. Still in Advanced Parameters > Webservice, click Add new webservice key
2. Configure the key with the following settings:

Basic configuration

• Key: Click Generate to obtain a unique 32-character key (or enter a custom one)
• Key description: Add a clear description (e.g. "Order Invoicer - Sellsy Integration")
• Status: Enable the key by selecting "Enabled"

Required permissions

Order Invoicer checks these permissions on connection and rejects the configuration if any are missing. Tick at least View (GET) for each resource below:

• ✅ addresses — billing and shipping addresses
• ✅ carriers — carriers used on orders
• ✅ combinations — product combinations (sizes, colors, etc.)
• ✅ countries — countries of customer addresses
• ✅ currencies — order currencies
• ✅ customers — customers
• ✅ order_details — order line items
• ✅ order_payments — order payments
• ✅ order_slip — credit notes / refunds
• ✅ orders — orders
• ✅ products — products
• ✅ shops — shops (required to identify your installation)
• ✅ taxes — taxes applied to orders

Tip: in the PrestaShop screen, use the Select all link at the top of the View (GET) column to save time, then untick only the resources you do not want to expose access to.

Optional permissions

Only required if you use these features:

• stock_availables — View + Edit (PUT) if you sync stock from your invoicing tool to PrestaShop
• customer_threads, customer_messages, contacts — View + Add (POST) if you want Order Invoicer to create customer service tickets on invoicing events
• groups — View (GET) if you use PrestaShop customer groups as pricing grids and want them synced to your customers (shown on orders). Without it, sync still works — groups are simply omitted.
• tax_rule_groups, tax_rules — View (GET) to record the VAT rate your shop actually applies instead of inferring it from the order amounts. Without them, sync still works — the rate is derived from the totals.

Multistore configuration (if applicable)

• Shop association: In multistore mode, choose the shops the key gives access to
• If you have several shops, select only the ones you want to connect

3. Click Save to create the key

3. Retrieve the connection details

After creating the key, note the following details:

• Your store URL: https://your-store.com
• API key: The generated key (32 characters)

Important: Keep this information secure. You will need it to configure the connector in Order Invoicer.

Verifying the configuration

API test

To verify that your key works, request a single resource with it — pass the key in the ws_key query parameter:

https://your-store.com/api/orders?ws_key=YOUR_KEY&limit=1

You should get an XML response containing one order. If you get:

• 401 or 403: the key is disabled or lacks View (GET) on that resource — recheck the key status and its permissions.
• An error on https://your-store.com/api/ (the root): this alone does not mean the key is broken. On many installs the webservice root returns a 500 or an HTML page even when the individual resource endpoints work fine, so always test a specific resource as shown above rather than the bare /api/ URL.

Common troubleshooting

"Webservice not enabled" error

• Check that the webservice is enabled in Advanced Parameters
• Restart the PrestaShop cache if necessary

"Invalid API key" error

• Check that the key is exactly 32 characters
• Make sure the key is active
• Check the granted permissions

"Access denied" error

• Check that your store URL is correct
• Make sure your site is accessible over HTTPS
• Check the permissions of the API key

"Missing permissions: …" error Order Invoicer indicates exactly which resources are missing. Go back to the webservice key and tick View (GET) for each of the listed resources, then restart the configuration.

Support

If you run into difficulties:

1. Check the troubleshooting section above
2. Consult the official PrestaShop documentation
3. Contact our support: contact@orderinvoicer.com

Next steps

Once your key is configured and the connector is created in Order Invoicer:

• Install the PrestaShop module for near-instant order sync (optional).
• Disable PrestaShop invoices so your invoicing tool owns invoice numbering.