On the Alibaba platform, when buyers pick up the goods themselves, the seller usually prepares the goods and the buyer comes to pick them up. In this case, the seller can collect payment through the following steps:

1. When the buyer comes to pick up the goods, the seller can ask the buyer to confirm receipt.

2. After the buyer confirms receipt, the Alipay system will automatically transfer the payment to the seller's Alipay account.

3. If you need to collect payment in advance, the seller can activate the "City E Credit Account" function, and then select an unfinished order to collect payment in advance.

4. Please note that the specific operation may vary depending on personal account settings and the nature of the order. It is recommended that you read the relevant guidelines carefully or confirm with the customer service staff before operation.