This extension (Pixiv Infinite Scroll) processes all data locally and does not send any data externally.
The handling of data is as follows:

CSRF Token

• To provide bookmark and follow functions, the CSRF token is temporarily stored in memory.
• This token is only used when making requests to the pixiv API.

• User settings such as mute words are only stored in the browser's local storage.
• These settings are only used for the operation of the extension and are not sent externally.

• To provide the mute function, the extension monitors API requests made by pixiv.
• Content is filtered on the client side based on the mute words set by the user.