To take action on your behalf, Phantombuster needs to authenticate as you. To do this, it needs (some of) your session cookie(s).
Or, you can find them manually. Here's how:
What are session cookies?
They are one string of text generated by the websites you connect to when you log in and stored on your computer.
Don't worry! Phantombuster doesn't know your password, nor your email address, and these cookies reset when you manually log out of a website.
How to get your cookies manually
Open a new tab and go to the website whose cookies you're after.
Right-click anywhere on the page and open the inspector:
Locate the 'Application' tab:
Then select 'Cookies' > 'http://www.websiteyoureafter.com':
Locate the cookie you're looking for:
So, for example, for LinkedIn you'll be looking for the 'li_at' cookie's value:
Copy this and paste it back into your Phantom's configuration.
You're all set!