How to read/write custom entities?

Shopware 6 (English)
1

We are writing a plugin (not an App) and we have defined a custom entity in „entities.xml“ as described here: Custom entities | Shopware Documentation. This works: the database tables are created (for the custom_entity_bundle in the doc the tables custom_entity_bundle, custom_entity_bundle_products, custom_entity_bundle_translation are created).

Now we want to read/write to the custom_entity_bundle table. According to the doc

All registered entities will get an automatically registered repository.

HOW DO WE GET THIS REPOSITORY?

We have tried the obvious: inject it as custom_entity_bundle.repository . Result:

The service „MyCoolPlugin\Service\SomePriceCalculator“ has a dependency on a non-existent service „custom_entity_bundle.repository“. Did you mean this: „custom_entity.repository“?

<!-- MyCoolPlugin/src/Resources/config/services.xml ... container ... services ... -->
<service id="MyCoolPlugin\Service\SomePriceCalculator" decorates="Shopware\Core\Content\Product\SalesChannel\Price\ProductPriceCalculator">
  <argument type="service" id="MyCoolPlugin\Service\SomePriceCalculator.inner" />
  <argument type="service" id="WHAT_GOES_HERE" />
  <!--                         ______________ -->
</service>

If we really have to use the custom_entity.repository (as suggested in the error message), how would we use this to read/write custom_entity_bundle entities?