PayPal invoice status not updating after successful payment

[Edqe_]

I use the invoicing API to make an invoicing discord bot. I managed to use the API to make the invoice and send the link to the chat for the recipient to pay it but after testing using sandbox account, the payment stated as pending and the transaction didn't show on the merchant side and the invoice status still UNPAID or SENT.

Invoicing API v2

Language: NodeJS

Package used: https://www.npmjs.com/package/paypal-invoices

Invoice object

{
        detail: {
          invoice_number,
          currency_code: config.invoice.currency,
          note: config.invoice.details.note,
          term: config.invoice.details.term,
          payment_term: {
            term_type: 'NET_15'
          }
        },
        items: [
          {
            name: item,
            quantity: '1',
            unit_amount: {
              currency_code: config.invoice.currency,
              value: amount.toFixed(2)
            },
            unit_of_measure: 'AMOUNT'
          }
        ],
        configuration: {
          partial_payment: {
            allow_partial_payment: true,
            minimum_amount_due: {
              currency_code: config.invoice.currency,
              value: (amount * 0.5).toFixed(2)
            }
          },
          allow_tip: true
        }
      }

Recipient side (both is partial payment)

Invoice

I think its just pending payment but since the API stated there is pending payment status so I don't really know what happened