Check typography addon active or not and load options according.

gistfile1.txt

$customizer_data = get_option( 'astra-settings', array() );

$is_typo_addon_active = is_callable( 'Astra_Ext_Extension::is_active' ) ? Astra_Ext_Extension::is_active( 'typography' ) : false;

for ( $i = 1; $i < 7; $i++ ) {
	if ( ( ( $i > 3 ) && ( true === $is_typo_addon_active ) ) || ( $i < 4 ) ) {
		if ( isset( $theme_settings[ 'font-size-h' . $i ] ) && '' !== $theme_settings[ 'font-size-h' . $i ]  ) {
			$elementor_page_settings[ 'astra_sites_heading_' . $i . '_typography' ] = 'custom';
			$elementor_page_settings[ 'astra_sites_heading_' . $i . '_font_size' ]  = array(
				'unit' => $theme_settings[ 'font-size-h' . $i ]['desktop-unit'],
				'size' => (int) $theme_settings[ 'font-size-h' . $i ]['desktop'],
			);

			if ( '' !== $theme_settings[ 'font-size-h' . $i ]['tablet'] ) {

				$elementor_page_settings[ 'astra_sites_heading_' . $i . '_font_size_tablet' ] = array(
					'unit' => $theme_settings[ 'font-size-h' . $i ]['tablet-unit'],
					'size' => (int) $theme_settings[ 'font-size-h' . $i ]['tablet'],
				);
			}

			if ( '' !== $theme_settings[ 'font-size-h' . $i ]['mobile'] ) {

				$elementor_page_settings[ 'astra_sites_heading_' . $i . '_font_size_mobile' ] = array(
					'unit' => $theme_settings[ 'font-size-h' . $i ]['mobile-unit'],
					'size' => (int) $theme_settings[ 'font-size-h' . $i ]['mobile'],
				);
			}
		}
	}
}