The extension finds a work email address for a LinkedIn profile you have open. This page lists every piece of data it touches. It is short because the extension does very little.
When — and only when — you click Find work email, the extension reads two things from the profile page you already have open: the person's name and their employer's name, as displayed. That is the entire collection. It does not read an email address from the page; LinkedIn does not display one, and the extension contains no code that would extract one if it did.
Those two fields, together with the connection key for your account and the extension's install identifier, are sent to app.leadprove.com — LeadProve's server. There is no other destination. The extension makes no other network request and calls no LinkedIn endpoint.
When you press Connect to LeadProve, the extension opens your LeadProve dashboard. Once you are signed in, the dashboard creates a connection key for your account and hands it to the extension directly; only app.leadprove.com can do this. You can disconnect in the extension's Settings, or revoke the key in your dashboard's Extension tab.
In your browser's extension storage, on your device only: the connection key for your account and the email it is connected as, your daily lookup cap, a count of lookups used today, and a random install identifier. Uninstalling the extension deletes all of it.
The install identifier is a random value created when the extension is installed. It is sent with each lookup so LeadProve can tell when one installation is used with several free accounts. It contains nothing about you or your browser.