Sometimes in Facebook transaction reports there is no campaign owner name to identify a fundraiser. When this happens GivePanel uses the name "Supporter" instead of the fundraiser name (campaign owner name).
This means that in the Message Templates and Data Capture Forms the word "Supporter" will appear instead of "First name".
Facebook will usually sort this for you over time, simply try requesting a fresh report a few hours / days later for the same time period and re-uploading this into GivePanel. If Facebook have updated the data with the actual names of your fundraisers this will update in GivePanel too.
If you can't wait for Facebook to sort this, you can resolve this quickly by editing their name when you're in their record in GivePanel, changing it from supporter to their actual name.