For taking charitable donation items to a donation center, and not working directly for a charity, can you claim round trip mileage, or, only one way mileage?

Round trip appears the proper answer if exclusively for the donation purpose. Found conflicting answers regarding if the mileage is deductible for traveling to a donation Center to donate, or, deductible only when working for a charitable organization. Need a clarification on the circumstances for when you can claim charitable mileage.