Since its an open profile you can click on edit and add the source under "sources".
Once you add a source you need to go to the edit page, look at the "Biography section" and any where you see <<ref>> source needed <</ref>>> or words like it, just take it out of the sentence it was added to. It is usually placed by the birth or death date.
In addition, on the top of the page where the word Biography is, there should be something that looks like {{source needed}} above it... take that out.
