I am building a module that contains a route and a controller that only renders a specific theme region, without any surrounding HTML.
How can I load and render the region programmatically within the controller output method?
The region output from the controller contains one or more blocks and the entire region needs to be embedded on another site. The site will retrieve the markup using a custom route (e.g. example.com/partials/header or example.com/partials/footer).
I don't know which blocks are going to be in the region; the list of blocks in the region is not hard-coded in the module.