Probably many pilots had a problem with performing Lost cargo side tasks from G&B, which are offered in a location called Nephtys Plains.
Lost Cargo Jobs Guide
So, you took the task to search for cargo, flew to the desired location, but in the places where the marker points, there are only debris or a large asteroid. Are you wondering where is the container you need? You search for containers for a long time and find nothing. But you don't have to look for containers. You need to look for yellow flashing lights.
So, these lights are the containers we need. Fly up to them and take it. Then deliver them to the station. That's all.
By the way, each container occupies one inventory cell, so make sure that you have from 2 to 6 cells free.
A small addition: sometimes there are missions where you can find several task markers. So, this markers dissappear after you collect all containers nearby that marker.