The form splits into two groups and the distinction is deliberate.
Contact Information is you, the requester, meaning Full Name and Contact Email, both required. This is where UpLead replies.
Requested data holds Email and Phone Number, the record you want acted on. Fill in at least one or the form refuses to send, with the message "Please fill in Email or Phone Number for removal." Use the work address and the mobile as they'd appear in a sales database.
UpLead spells out that the two groups can differ, saying the contact email "can be different or the same as the email you request data for". That's the useful bit if the listed address belongs to a job you've already left.
The phone field takes digits only, no spaces, brackets or dashes. Start with the country code (1 for a US number), because the form puts a plus sign in front of whatever you type and reads it as an international number.