I'm trying to create a warning command that DMs the specified user to notify them. Here is the specific code I'm trying to use:

    const user = await client.users
      .fetch(interaction.options.getString("user"), false)
      .catch(() => null);
    console.log(interaction.options.getString("user"));
    const embed = new MessageEmbed()
      .setColor("#FCE100")
      .setTitle(`⚠️ Warning!`)
      .setDescription(`${interaction.options.getString("warning")}`);
    await user.send({ embeds: embed }).catch(() => {
      interaction.channel.send(
        "Error: user not found"
      );
    });

The getString for user is correctly getting the user, as I've tested from console.log(). I can only assume the syntax is somehow wrong, although I can't seem to find the correct way to do this. The only error I'm getting is:

TypeError: Cannot read properties of null (reading 'send')