Just read the description:
https://www.esoui.com/downloads/info...Writ.html#info
Install it and all needed dependencies named there into your AddOns folder.
Activate the libraries/dependencies and the addon at the character selection screen.
Go ingame and check the addon is enabled.
Press ESC-> setings -> Addon settins and check if there is a Confirm Master Writ entry, like with every addon.
Setup the addon there to your needs.
Check the tooltip of a writ if the info is added.
If not: Tell the addon dev in the addon comments or in his/her bug panel.