How to search for multiple cards at once?

Hi there. I’m trying to search for multiple MTG cards at a time to save on API calls, but I seem to be unable to search for more than one at a time.

    const body = {
      filters: [
        {
          values: ["Channel"],
          name: "ProductName",
        },
      ],
    };
    await fetch(url, {
      method: "POST",
      body: JSON.stringify(body),
      headers: headers,
    })

The above code returns several productIds. Yet when I try to add another item to the value array like the code below, I get no results. No errors, but also no results.

    const body = {
      filters: [
        {
          values: ["Channel", "Fireball"],
          name: "ProductName",
        },
      ],
    };
    await fetch(url, {
      method: "POST",
      body: JSON.stringify(body),
      headers: headers,
    })

More than anything I’m confused, because it’s not working as I expected it to. Why is ‘values’ an array when it doesn’t work when I add more items? And if it’s not supposed to work that way, then how would one recommend getting productIds for multiple cards with a single api call?

its an array because other filters can have multiple values (such as rarity) but the structure of filters[] needs to be consistent.

It would be nice if they upgraded the API to have this feature.