Profile view, connection request and message steps run through the Chrome extension on your own account.
Open a sequence from "Sequences".
Click "Add step".
"LinkedIn Profile View" visits the profile so you show up in their notifications.
Click "LinkedIn Connection Request".
Write the note (optional, 300 characters). Fields work here too.
Choose what happens when you hit the daily LinkedIn limit: wait and retry tomorrow, or skip the step.
Click "Save Step". The step runs when you press "Run in Chrome" in Message Center.
Open "Add step" again.
"Manual Social Step" is for anything else: a comment, a follow, a DM you write yourself. It becomes a task.