Set Minimum total purchase amount

add_action( 'woocommerce_check_cart_items', 'required_min_cart_subtotal_amount' );
function required_min_cart_subtotal_amount() {
    // HERE Set minimum cart total amount
    $minimum_amount = 200;
    // Total (before taxes and shipping charges)
    $cart_subtotal = WC()->cart->subtotal;
    // Add an error notice is cart total is less than the minimum required
    if( $cart_subtotal < $minimum_amount  ) {
        // Display an error message
        wc_add_notice( '<strong>' . sprintf( __("A minimum total purchase amount of %s is required to checkout."), wc_price($minimum_amount) ) . '</strong>', 'error' );
    }
}