I have built a plugin (1020.0.19) that I installed on a management tenant. It works; however, when trying to provide the extended app, including the plugin, to the sub-tenants, it doesn’t seem to load.
Do I need to add a configuration to enable the plugin for multi-tenancy, or am I missing something else?
I guess you mean subscribing them from the management tenant to a subtenant?
Can you verify via your browsers network tab, whether the shell application is trying to loads a remoteEntry.js file after logging into your shell app? It should be loaded from /apps/<contextPathOfYourPlugin>@<versionOfYourPlugin>/remoteEntry.js.
If you can not find such a request, the plugin was probably not installed correctly into your shell application.
If you found such a request, but it did not return a 200 status code (instead most probably a 404 status code), then your plugin is not accessible from your subtenant. In that case you would either need to set the availability of your extension to SHARED/PUBLIC or you explicitly subscribe your extension to your subtenant.
In case you found the request with a 200 status code, your plugin should have loaded. If it still does not show up, it would be helpful if you could provide both the platform details (that you can download via the button in the right drawer) and the console log of your browser.