Can I also use LinkOne / LinkTwo for charging sessions that are not billed through my employer?

Yes, you have the option to mark each individual charging session as reimbursable or non-reimbursable. Only the charging sessions you have marked as reimbursable will be included in the receipt submitted to your employer. You can make this selection in the app by tapping on the respective charging session and toggling the "Reimbursable" option on or off.