Besides this description, see what old app is doing.

User can edit repositories and add new ** repos with approve pipeline or staging pipeline. In last version, there where only one repository "published" and one repository "staging", so approve operation simply called move endpoint to move collection from current staging repo to published repo - or rejected repo to published repo, if user is approving previously rejected collection.

Now in current version with user defined repositories, in approve list, we will get repositories by pipeline approved. Then after clicking approved, If only one repo found, we will simply move the collection to the first found approved repo. If multiple repos found, we have to run the modal.

The modal will have PageTable with repository simplified list - columns name and description, filters by repository name. It will have multiselection. User will be able to select repos it wants to publish the collection into them. After submitting the operation, we can run copy api endpoint -  there is multiple copy endpoint (used in old codebase) that accepts original repo and list of destination repos. It then copies collection from original repo to selected repos (and finaly, deletes it from original repo).

The approve operation in the approval list will be enabled (not blurred) only when collection is in the rejected or pipeline staging repo - you have to watch the pipeline, not the name "staging", because we can have multiple staging type repos and they dont have to be named "staging". But there will be one rejected repo called rejected, user cant create its own rejected repos.

Dont also forget to pass the signing service (see it in the old codebase). We will have also to check for RBAC, if the user have rights to approve collection - it seems old codebase does not do that.

Tallk with UX (for example Anastasia Ratti) if they want to do it as modal, or separate page.