The phrase "to require a signature" means that someone needs to sign their name on a document or package as proof that they have received it. Full definition
Many of these documents require a signature from all parties involved to be considered legally binding. (lawyer-monthly.com)
If the seller doesn't provide you with any, or doesn't require your signature on an agreement, you should be wary. (feedspot.com)
The law requires signatures equal to 4 % of the number of registered voters, or approximately 20,000 valid signatures in the typical district. (thirdpartypolitics.us)