Value decimals in legend

[VIMVa]

I love Plotly but I am a newbie at coding.
Can anyone help.
I have this graph comparing 2 values of air pressure, both from a sensor in ESPHOME, rounded to 1 decimal there.
Whatever I try and wherever I Google, I am unable to find a way to show that 1 decimal in the legend. I have none or a bunch of decimals:

I know of 2 expressions to show the latest value in the legend:

    name: |
      $ex "Woonk " + Math.round(ys[ys.length - 1])

gives 0 decimals and

    name: |
      $ex "Bureau" + ys[ys.length - 1]

shows these weard value with a lot of decimals.
The full code:

type: custom:plotly-graph
entities:
 - entity: sensor.temp_003_luchtdruk
    name: |
      $ex "Woonk " + Math.round(ys[ys.length - 1])
    mode: lines
    connectgaps: true
    line:
      width: 2
      color: brown
  - entity: sensor.pres001_luchtdruk
    name: |
      $ex "Bureau" + ys[ys.length - 1]
    mode: lines
    connectgaps: true
    line:
      width: 2
      color: green
hours_to_show: 2d
refresh_interval: 10
fn: |
  $fn({getFromConfig, vars})=> {
    const range = getFromConfig("visible_range");
    const width = range[1] - range[0];
    vars.scroll = (label, p) => ({
      args: [
        {
          layout: {
            "xaxis.range": [range[0] + width*p, range[1] + width*p],
          }
        }, {
          transition: {
            duration: 150,
          }
        }
      ],
      label,
      method: "animate",
    })
    vars.zoom = (label, h) => ({
      args: [
        {
          layout: {
            "xaxis.range": [Date.now()-1000*60*60*h, Date.now()],
          }
        }
      ],
      label,
      method: "animate",
    })
  }
layout:
  updatemenus:
    - buttons:
        - $fn({vars}) => vars.scroll( '<', -1)
        - $fn({vars}) => vars.scroll( '>', 1)
      direction: right
      active: -1
      pad:
        r: 10
        t: 10
      type: buttons
      x: 1
      xanchor: right
      "y": 1.3
      yanchor: top
    - buttons:
        - $fn({vars}) => vars.zoom( '7d', 24*7)
        - $fn({vars}) => vars.zoom( '3d', 24*3)
        - $fn({vars}) => vars.zoom( '1d', 24)
        - $fn({vars}) => vars.zoom( '6h', 6)
        - $fn({vars}) => vars.zoom( '1h', 1)
      direction: right
      active: -1
      pad:
        r: 10
        t: 10
      type: buttons
      x: 0
      xanchor: left
      "y": 1.3
      yanchor: top
  height: 500
autorange_after_scroll: true
defaults:
  yaxes:
    autorange: true

Anyone?