Custom tables on Angular Web

You are correct you will need to create a custom API plugin.

namespace CCC.CompositionApi.Server.Plugin
{
    public class CustomTablePlugin : IApiProviderFor<PortalApiProject>
    {
        public void Build(IApiBuilder builder)
        {
            builder.AddMethod(Method
                .Define("customtable/demo")
                .FromTable("CCCDemo")
                .EnableRead()
                .WithAllColumns());
        }
    }

Identity Manager | Angular Web Development #20 | API Server Extension Dev
OneIdentityManager.9.2.1.zip: Modules\QBM\dvd\AddOn\ApiSamples
For study purposes you could take a peek into the QER.CompositionApi.Server.PlugIn.dll for more advanced examples like Method.Define("person/all") or Method.Define("person/active")

You are correct you will need to create a custom API plugin.

namespace CCC.CompositionApi.Server.Plugin
{
    public class CustomTablePlugin : IApiProviderFor<PortalApiProject>
    {
        public void Build(IApiBuilder builder)
        {
            builder.AddMethod(Method
                .Define("customtable/demo")
                .FromTable("CCCDemo")
                .EnableRead()
                .WithAllColumns());
        }
    }

Identity Manager | Angular Web Development #20 | API Server Extension Dev
OneIdentityManager.9.2.1.zip: Modules\QBM\dvd\AddOn\ApiSamples
For study purposes you could take a peek into the QER.CompositionApi.Server.PlugIn.dll for more advanced examples like Method.Define("person/all") or Method.Define("person/active")