It’s required turn on the WordPress permalinks at: Settings > Permalinks.
To enable the REST API within WooCommerce, go to WooCommerce > Settings > API and tick the Enable REST API checkbox.
The WooCommerce REST API works on a key system to control access. These keys are linked to WordPress users on your website.
To create or manage keys for a specific WordPress user:
1/ Go to: WooCommerce > Settings > API > Keys/Apps.
2/ Select Add Key.
3/ Select the User you would like to generate a key for in the User field and add a Description.
4/ Choose the level of access for this API key, which can be Read access, Write access or Read/Write access.
5/ Select the Generate API Key button, and WooCommerce will generate API keys for that user.
Now that keys have been generated, you should see two new keys, a QRCode, and a Revoke API Key button. These two keys are your Consumer Key and Consumer Secret.
6/ Place your consumer key and consumer secret in the application that uses the WooCommerce API (the application should request your URL as well).