You can use the "Find Institutes & Courses" interface on the website to filter schools that offer online courses. For information on course fees, please refer to the respective school's Mandarin center website.
Additionally, Taiwan's official free online Mandarin resources include the Mandarin Learning section on the Ministry of Education's "edu MOOCs +" platform , the "Learning Chinese: Start From Scratch" course on Coursera, "Intermediate Chinese"on Coursera, and the "MITx: Chinese Language in Culture: Level 1-3" course on edX. These diverse courses are available for learners to choose from according to their personal needs.