> For the complete documentation index, see [llms.txt](https://docs.rishvi.co.uk/linnworks/llms.txt).
> Use it to discover all available pages before exploring further.
# Self-signed certificate for ePOS printers
Some ePOS printers require a secure HTTPS connection to communicate with Odoo. This guide explains how to generate, export, and install a self-signed certificate to enable secure communication.
Certain ePOS printers that operate without an IoT system require HTTPS to establish a secure connection with the browser. Since these printers use self-signed certificates, browsers may display a warning when accessing their IP address.
To resolve this, you must generate, export, and import a self-signed certificate.
## **Overview**
Self-signed certificates are used to:
- Secure communication between the browser and the printer
- Eliminate browser security warnings
- Allow proper integration with Odoo POS
**Important**
- A self-signed certificate should only be generated **once**. Creating a new one invalidates previously trusted certificates
- Printers connected via an **IoT system** do **not** require this setup
- For best results, use **Google Chrome** during configuration
**Note**
If your operating system or browser differs from the examples below, search for:
- `export SSL certificate `
- `import SSL certificate root authority `
## **Generate a self-signed certificate**
Steps may vary depending on your system, but the process below uses Google Chrome.
1. Open your browser and enter the printer’s IP address (e.g., `https://192.168.1.25`)
2. On the security warning page:
- Click **Advanced**
- Select **Proceed (unsafe)**
3. Access the printer’s admin interface:
- Go to **Advanced Settings → Administrator Login**
4. Enter the default password (usually found on the printer)
5. Navigate to:\
**Network Security → SSL/TLS → Certificate**
6. Under **Self-signed Certificate**, click **Update**
7. Set the **Common Name** to the printer’s IP address only
8. Confirm and wait until the printer finishes processing
**Note**
Login credentials may vary by model. For example, some Epson printers use:
- Username: `epson`
- Password: printer serial number
## **Export the certificate**
After generating the certificate:
1. Click the **Not secure** label in the browser address bar
2. Open **Certificate details**
3. Go to the **Details** tab
4. Click **Export**
Then:
- Save the file with a `.crt` extension
- Use format: `Base64-encoded ASCII`
## **Import the certificate**
To trust the certificate on your system:
1. Open browser settings
2. Navigate to **Privacy and security → Security**
3. Click **Manage certificates**
Then:
1. Open the certificate manager
2. Click **Import**
3. Select your `.crt` file
4. Choose:
- **Trusted Root Certification Authorities**
5. Complete the wizard and confirm
**Note**
Import steps may vary depending on your OS or browser (Chrome, Firefox, etc.).
## **Verify the connection**
To confirm the setup:
1. Open the printer’s IP using HTTPS
- Example: `https://192.168.1.25`
2. Check the browser:
- No security warning should appear
- A 🔒 padlock icon should be visible in the address bar
This confirms a secure connection between the browser and the printer.