Popular listings often receive multiple requests, so you need to wait for a confirmation message to ensure the item is yours. You can check a user's profile to see how responsive they are before making a request.
You will receive a message, similar to below, once the listing is confirmed:
Jane has just confirmed that you're collecting 'Sandwich'. Great job!
🚫 Please do not set off and assume a pickup unless you have received a confirmation of the exact time and location of the pickup.