Look at the permissions for the extension.  It clearly states they will be able to "Read and Change your data" on twitter.com https://i.postimg.cc/8PqH4ydL/SNAX.png

In their Privacy Policy (https://snax.one/privacy-policy), it states they will capture, among other things, PASSWORDS. (see Section 2).  In Section 4, it states the purpose will be for Snax to manage contacts and send messages, interaction with external social networks and platforms, etc. 

Further on it describes integration with Mailchimp but does not state if it is only for the subscribed user or if they are harvesting the emails of those you connect with.