What do I do if I cannot find the delivery address?

Contact the customer through the app first. It keeps the conversation on the platform's record, which matters if the delivery is later disputed, and most problems are a wrong flat number rather than a wrong street.

If there is no answer, use in-app support and follow their process. Every platform has one, and following it is what protects you when a customer claims the item never arrived.

Do not leave it somewhere and hope. An unrecorded drop is the fastest route to a complaint you cannot defend, and complaints are one of the common causes of deactivation.

Photograph what you did, where you left it, or the door you could not get an answer at. A timestamped photo is worth more than a recollection three weeks later.

The time spent on this is still working time and the miles are still business miles. Log the shift by the hours it actually took, including the twenty minutes lost to a wrong postcode, because that is what the job really paid.