public static bool GetHasActivationExtension( 
   Table table,
   Guid extensionId
)

public void ExtensionIds1(Table table)
{
    //Add an extension id to a table
    //Check documentation for restrictions on backward compatibility - backward
    //compatibility is limited to ArcGIS Pro 3.1 if an extension id is added.
    //Note: This is an extension method. It is for use in addins only and not CoreHost.
    string extension_id_string = "52d8f3be-b73d-4140-beaf-23d4f9b697ea";
    Guid extension_id = Guid.Parse(extension_id_string);

    //Note: Must be within the lambda of QueuedTask.Run(() => { ...

    //register the extension id with the relevant table
    table.AddActivationExtension(extension_id);

    //Remove an extension id from a table
    //Restores backward compatibility assuming no other compatibility limitations are
    //in place.
    //Note: This is an extension method. It is for use in addins only and not CoreHost.
    table.RemoveActivationExtension(extension_id);

    //Check if a given extension id  is registered with a particular table.
    //Note: This is an extension method. It is for use in addins only and not CoreHost.
    if (table.GetHasActivationExtension(extension_id))
    {
        //TODO - implement custom logic relevant to presence of extension_id
    }

    //Enumerate all extension ids on a given table.
    //Note: This is an extension method. It is for use in addins only and not CoreHost.
    foreach (Guid ext_id in table.GetActivationExtensions())
    {
        //TODO - logic based on extension ids
    }
}