Put the command pickup into the F1 console to see and use the commands

pickup add <amount> <itemid> | add a pickup at your location | -rotate changes the default orientation -axis changes the rotation axis (play with these if it doesn't look right)
pickup kill | kill the nearest pickup | -all kills all pickups
pickup respawn | respawns all the pickups immediately
pickup cooldown <duration> | set the respawn cooldown for the nearest pickup | -all applies to all pickups
pickup save | Save the current config