Read about whitelisting your store url before you can accept payments on your woocommerce store. 
- Log in to your Wordpress Admin Dashboard.
- Search for the downloaded plugin, extract and copy this plugin in the plugin folder (/wp-content/plugins) of your website.
- Activate plugin Telr from Wordpress Plugins Page.
- Go to Settings in WooCommerce, click Checkout and select Telr in Payment Gateways section.
- Select the checkbox against Enable/Disable field.
- Enter your Telr Payment Gateway App Id and Secret Key.
- Click on Enable Telr sandbox to enable sandbox if required.
- Click on Enable In Context to use without redirection payment flow.
- Click Save Changes.
If you see an “Authentication Failed” error message during integration, please clear the option “Enable Telr Sandbox” in the WooCommerce plugin Settings page.
