如何获取外部ID

看起来您正尝试获取用户的 user_associated_account.provider_uid。从代码来看,有一个隐藏的站点设置需要启用,才能使 associated_account_ids 从 CurrentUserSerializer 返回:

include_associated_account_ids 设置是隐藏的:discourse/config/site_settings.yml at main · discourse/discourse · GitHub Rails 控制台并运行:

SiteSetting.include_associated_account_ids=true