Enforcement Rules for the Document Legalization Act for the Ministry of Foreign Affairs and Overseas Missions Article 2

Applicants or their agents seeking document legalization in the Republic of China (hereafter, “the ROC”) in accordance with this Act shall submit their application in person to the Ministry of Foreign Affairs. Overseas, applicants or their agents shall submit their application to the relevant overseas mission in person or by mail. The latter option will only be available where overseas missions have duly indicated that they accept mail-in applications.
中文原文 外交部及駐外館處文件證明條例施行細則第2條
依本條例申請文件證明,在國內由申請人或其代理人至主管機關辦理;在國外由申請人或其代理人至駐外館處或以郵寄方式辦理,但以郵寄方式辦理者,以經駐外館處以適當方式周知受理者為限。

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