I'm trying to push to an array some values from a select box, when clicking a button but I get this error.

Uncaught TypeError: Cannot read property 'push' of undefined

My code for the button is

el(IconButton, {
    icon: 'plus',
    label: 'Add',
    onClick: function(e){
         list.push(postID)
         console.log(list)
    }
})

Of course i declared these attibutes

attributes: {
    postID: {
        type: 'number',
    },
    list: {
        type: 'array'
    }
}

postID get updated every time when the select box changes, and what I'm trying to do it's to add the postID value to an array of values

Full block code:

var teams = [];
$.getJSON('/wp-json/wp/v2/team?per_page=100', function (data) {
    $.each(data, function (index, elem) {
        teams.push({
            label: data[index]['title']['rendered'],
            value: data[index]['id']
        })
    })
});

    (function (blocks, editor, components, i18n, element) {
        var el = wp.element.createElement
        var registerBlockType = wp.blocks.registerBlockType
        var SelectControl = components.SelectControl
        var IconButton = components.IconButton
        var InspectorControls = wp.editor.InspectorControls

        registerBlockType('valida/team', { // The name of our block. Must be a string with prefix. Example: my-plugin/my-custom-block.
            title: i18n.__('Team'), // The title of our block.
            description: i18n.__('team'), // The description of our block.
            icon: 'admin-users', // Dashicon icon for our block. Custom icons can be added using inline SVGs.
            category: 'valida-blocks', // The category of the block.
            attributes: { // Necessary for saving block content.
                postID: {
                    type: 'number',
                },
                list: {
                    type: 'array'
                }
            },
            edit: function (props) {
                var attributes = props.attributes
                var postID = attributes.postID
                var list = attributes.list
                return [
                    el(InspectorControls, {
                            key: 'inspector'
                        }, // Display the block options in the inspector panel.
                        el(components.PanelBody, {
                            title: i18n.__('Home section settings'),
                            className: 'block-home-section-settings',
                            initialOpen: true
                        }, ),
                        el('div', {
                                className: 'inspector-block'
                            },
                            el('ul', {
                                className: 'selected-list'
                            }),
                            el(SelectControl, {
                                className: 'team-selector',
                                label: 'Select member',
                                value: attributes.postID,
                                options: teams,
                                onChange: function (id) {
                                    props.setAttributes({
                                        postID: id
                                    })
                                },
                            }),
                            el(IconButton, {
                                icon: 'plus',
                                label: 'Add',
                                onClick: function(e){
                                    list.push(postID)
                                    console.log(postID)
                                }
                            })
                        )
                    ),
                    el('div', {
                        className: props.className
                    })
                ]
            },

            save: function (props) {
                return null
            }
        })

    })(
        window.wp.blocks,
        window.wp.editor,
        window.wpponents,
        window.wp.i18n,
        window.wp.element
    )