Change LTR to RTL using code.

functions.php

add_action( 'init', 'astra_set_direction' );

function astra_set_direction() {
	global $wp_locale, $wp_styles;
	$direction = 'rtl';
	$wp_locale->text_direction = $direction;
	if ( ! is_a( $wp_styles, 'WP_Styles' ) ) {
		$wp_styles = new WP_Styles();
	}
	$wp_styles->text_direction = $direction;	
}