How to use tftp

how do i use tftp server on Ubuntu 18.10? i am a noob and i do not know how to use terminal to use root and all. can somebody help me setup tftp server so i can flash my Wavlink WL-WN575A3? please and thanks and also how to i back up the factory image as wavlink does not provide firmware downloads

tftpd-hpa, which can be configured via /etc/default/tftpd-hpa - which should be mostly self explaining.


thank you i will try to follow the instructions from the link you provided