1. Create a custom sub module, "Single Content Sync REST
2. Create a custom config entity "Consumer"
2.1. Add the following properties
URL
Username
Password
Active
Weight
3. Create the form to be able to create/edit the entity
4. Use built in core handlers e.g. form delete, permissions
5. Define a custom permission
6. Display a list of consumbers under /admin/config/content/single-content-sync/consumers
6.1. It should be drag-n-drop, so weight is updated. See how it's done in /admin/config/regional/language
Needs review
2.0
Code