Act Governing the Choice of Law in Civil Matters Involving Foreign Elements Article 23

An obligation arising from a management of the affairs of another without mandate (“negotiorum gestio”) is governed by the law of the place where the management was undertaken.
中文原文 涉外民事法律適用法第23條
關於由無因管理而生之債,依其事務管理地法。

English translation for reference only; the Chinese text prevails. Not legal advice.