Administrative Litigation Act Article 78

Service upon an R.O.C. ambassador/minister envoy/consul, or any other staff stationed in a foreign country shall be effectuated by the Ministry of Foreign Affairs requested to do so.
中文原文 行政訴訟法第78條
對於駐在外國之中華民國大使、公使、領事或其他駐外人員為送達者,應囑託外交部為之。

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