How to create a layout with two columns and a wide row at the bottom for PowerPoint?

[icarosadero]

Description

I would like to set up a layout where I have two plots side-by-side, followed with a wider one at the bottom. I tried this first:

---
format: pptx
---

::::{.columns}

:::{.column}
{{< placeholder 400 400 format=svg >}}
:::

:::{.column}
{{< placeholder 400 400 format=svg >}}
:::

{{< placeholder 900 100 format=svg >}}

However, the third figure is pushed to another slide when I render it. I have also tried to append --- at the bottom to specify the end of the slide, but the same issue occurred.

I am using quarto version 1.6.40 on Kubuntu 24.04.1

[mcanouil]

You are limited to the layout offered by Pandoc PowerPoint reference document.

The layout you want does not exist in it.

Note that .columns/.column is for "Two Content".

Could you also fix your code to be complete and reproducible as described when you've opened this discussion?
See the placeholder shortcode to include image: https://quarto.org/docs/authoring/placeholder.html