How to change field’s label on checkout page in woocommerce?

Solution:

/** * Add the field to the checkout */

add_action( ‘woocommerce_after_order_notes’, ‘my_custom_checkout_field’ );

function my_custom_checkout_field( $checkout ) {

echo '<div id="my_custom_checkout_field"><h2>' . __('My Field') . '</h2>';

woocommerce_form_field( 'my_field_name', array(

    'type'          => 'text',

    'class'         => array('my-field-class form-row-wide'),

    'label'         => __('Fill in this field'),

    'placeholder'   => __('Enter something'),

    ), $checkout->get_value( 'my_field_name' ));


    echo '</div>';

}

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