how to change the property value of an object nested in a tree of nodes?

Given the following data set, I need to change the value of the leaf property to true of the last nested element.

const data = [
    {
        label: "root",
        data: 1,
        expandedIcon: "pi pi-folder-open",
        collapsedIcon: "pi pi-folder",
        expanded: true,
        children: [
            {
                label: "Italy",
                data: 6,
                expandedIcon: "pi pi-folder-open",
                collapsedIcon: "pi pi-folder",
                expanded: true,
                children: [
                    {
                        label: "Bolognia",
                        data: 8,
                        expandedIcon: "pi pi-folder-open",
                        collapsedIcon: "pi pi-folder",
                        expanded: true,
                        children: [],
                        leaf: false, // <-- this need to be true
                    },
                ],
                leaf: false,
            },
        ],
        leaf: false,
    },
];

In this case the target is the object

{
    label: "Bolognia",
    data: 8,
    expandedIcon: "pi pi-folder-open",
    collapsedIcon: "pi pi-folder",
    expanded: true,
    children: [],
    leaf: false,
},

This tree will always have this structure, it can be extended or contracted indefinitely.

Having described the above, the expected result is the following

const data = [
    {
        label: "root",
        data: 1,
        expandedIcon: "pi pi-folder-open",
        collapsedIcon: "pi pi-folder",
        expanded: true,
        children: [
            {
                label: "Italy",
                data: 6,
                expandedIcon: "pi pi-folder-open",
                collapsedIcon: "pi pi-folder",
                expanded: true,
                children: [
                    {
                        label: "Bolognia",
                        data: 8,
                        expandedIcon: "pi pi-folder-open",
                        collapsedIcon: "pi pi-folder",
                        expanded: true,
                        children: [],
                        leaf: true, // <-- updated
                    },
                ],
                leaf: false,
            },
        ],
        leaf: false,
    },
];

I understand it can be achieved using recursion but I can’t identify how to do it. Thank you for your advices

update 1

I am trying the following to get the target node but I always get undefined

function tried(data) {
    if (data.children.length === 0) {
        return data;
    }

    tried(data.children[0]);
}

const output = tried(data[0]);

console.log(output);

>Solution :

You are going the right way, just missing the return on recursion call

const data = [
  {
    label: 'root',
    data: 1,
    expandedIcon: 'pi pi-folder-open',
    collapsedIcon: 'pi pi-folder',
    expanded: true,
    children: [
      {
        label: 'Italy',
        data: 6,
        expandedIcon: 'pi pi-folder-open',
        collapsedIcon: 'pi pi-folder',
        expanded: true,
        children: [
          {
            label: 'Bolognia',
            data: 8,
            expandedIcon: 'pi pi-folder-open',
            collapsedIcon: 'pi pi-folder',
            expanded: true,
            children: [],
            leaf: false,
          },
        ],
        leaf: false,
      },
    ],
    leaf: false,
  },
];

const getLastNestedElement = (data) => {
  if (data.children.length === 0) {
    return data;
  }

  return getLastNestedElement(data.children[0]); // you need to return
};

const lastNestedElement = getLastNestedElement(data[0]);
lastNestedElement.leaf = true;

console.log(JSON.stringify(lastNestedElement, null, 2));

console.log(JSON.stringify(data, null, 2));