If your Safe Drop request has been received too close to the time of delivery ?
We may need to adjust the Safe Drop depending on the weather or visibility to people passing by. If your Safe Drop request has been received too close to the time of delivery, we’ll let you know.

I don't get it:
If your Safe Drop request has been received "too close to the time of delivery"
i know " too....to " is about couldn't achieve something
but i still don't understand the meaning of this sentence.

Question

If your Safe Drop request has been received too close to the time of delivery ?
We may need to adjust the Safe Drop depending on the weather or visibility to people passing by. If your Safe Drop request has been received too close to the time of delivery, we’ll let you know.

I don't get it:
If your Safe Drop request has been received "too close to the time of delivery"
i know " too....to " is about couldn't achieve something
but i  still don't understand the meaning of this sentence.

Answer

'close to' means near. It means the two times are not far apart.
'too close' means overly close. In this case, they can't deliver in time if there is not enough time between the order and the delivery.
It can also relate to physical closeness: "You have a cold. Please don't get too close to me"

Answer

They mean if you haven't given them enough notice/time to change their plans. For example, they may need you to provide 12 hours notice. If you told them 4 hours before the delivery, then this would be 'too close'.