Include current user info in URL to external website

? How do I query and pass user info in a URL to an external website?

I want to be able to direct a user to an external info page and then log that they accessed the page. The logging would occur on the external website via the passed variables.

Example: https://externalwebsite.com?who=WP_USER_EMAIL_ADDRESS&name=WP_USER_NAME

I can easily echo all user data to a WP page or post but cannot get the info into a URL on those pages.