Apply this hooks in functions.php
remove_action( 'woocommerce_before_checkout_form', 'woocommerce_checkout_coupon_form', 10 );
add this action in your desired template
<?php
if ( ! function_exists( 'woocommerce_checkout_coupon_form' ) ) {
wc_get_template( 'checkout/form-coupon.php' );
} else {
woocommerce_checkout_coupon_form();
}
?>