You can enable and configure the external resource cache through the EMQX Dashboard:

1. Navigate to Access Control -> Authorization.

2. Click the External Resource Cache Settings button in the upper-right corner. A side panel will appear from the right.

3. In the panel, use the Enable External Resource Cache button to turn the caching feature on or off. Once enabled, configure the following cache settings:

   Field Name	Description
   Maximum Number of Cache Items	Maximum number of cached entries per node. Default: 1,000,000.
   Maximum Memory	Limit on cache memory usage. Default: 100 MB.
   Cache TTL	Duration a cached entry remains valid. Default: 1 minute.

4. Click Update to apply the settings.

These settings are applied cluster-wide to ensure consistent behavior across all nodes.