tl;dr
Add WooCommerce in Store Configurator → Data Sources → Add Data Source
Generate a Consumer Key and Secret in WooCommerce → Settings → Advanced → REST API
Paste both into Klar and click Connect WooCommerce Data Source
Data can take up to 24 hours to appear
Step 1: Add WooCommerce as a data source
In Store Configurator → Data Sources, click Add Data Source and select WooCommerce.
Step 2: Enter your store details
Name your data source — e.g. Brand Name Country. Then enter your Shop URL.
Step 3: Generate API keys in WooCommerce
In your WordPress backend, go to WooCommerce → Settings → Advanced → REST API and click Add key.
Give the key a description (e.g. "Klar"), set Permissions to Read, and click Generate API key. Then copy your Consumer key and Consumer secret.
Copy both keys now — the Consumer secret is hidden once you leave this page.
Step 4: Connect in Klar
Back in Klar, paste the Consumer Key and Consumer Secret into the form and click Connect WooCommerce Data Source.
Depending on how much data is involved, it can take up to 24 hours for your data to appear in Klar.