Associate existing community to created store

We are using B2B Commerce Lightning in Production. We created a Dev sandbox from Production. This restored Community Site but not Store.

Hence we used 'b2b-commerce-on-lightning-quickstart' to create Store & created one Store successfully. But any new Store created also creates its related Community site.

Here we want to associate newly created Store to an existing Community site. We found a junction object 'WebStoreNetwork' which maps Community Site (Network) to Store (WebStore). But its records are not editable or deletable.

We need your direction to associate newly created Store to an existing Community site.