Question Take all Cupons from inv Help

[SpiTik]

Can you help me i dont know how to create this function with command !all take all partner cupons to offer.

client.on("friendMessage", (partner, message) => {
  if(message === "!all"){
  const offer = manager.createOffer(partner);

      manager.loadUserInventory(partner, 753, 3, true, (err, theirInv) => {
          if (err) {
            console.log(err);
          } else {
            const theirItem =
              theirInv[Math.floor(Math.random() * theirInv.length - 1)];
            offer.addTheirItems(theirItem);

            offer.setMessage(
              `U cuppon`
            );
            offer.send((err, status) => {
              if (err) {
                console.log(err);
              } else {
                console.log(`Sent offer. Status: ${status}.`);
              }
            });
          }
        }
      );
}
});

[SpiTik]

I already have it 

  manager.loadUserInventory(partner, 753, 3, true, (err, theirInv) => {
          if (err) {
            console.log(err);
          } else {
            offer.addTheirItems(theirInv);

            offer.setMessage(
              `U cuppon`
            );
            offer.send((err, status) => {
              if (err) {
                console.log(err);
              } else {
                console.log(`Sent offer. Status: ${status}.`);
              }
            });
          }
        }
      );

Edited November 21, 2018 by SpiTik