Export gravity form entries every month

gistfile1.txt

function export_gf_entries(){
    
	$send_to = $_REQUEST['sendto'] ?? 'youremailhere';
	$form_id = $_REQUEST['fid'] ?? 1;
	
	$form = RGFormsModel::get_form_meta($form_id);
	$fields = array();

	if(is_array($form["fields"])){
		foreach($form["fields"] as $field){
			if(isset($field["inputs"]) && is_array($field["inputs"])){

				foreach($field["inputs"] as $input)
					$fields[] =  array($input["id"], GFCommon::get_label($field, $input["id"]));
			}
			else if(!rgar($field, 'displayOnly')){
				$fields[] =  array($field["id"], GFCommon::get_label($field));
			}
		}
	}
	
	$_grp_data = [];
	$line_data = [];
	foreach($fields as $fld){
		$line_data[] = $fld[1] ?? '';
	}
	//adjust headers
	$line_data[] = 'Created By (User Id)';
	$line_data[] = 'Entry Id';
	$line_data[] = 'Entry Date';
	$line_data[] = 'Date Updated';
	$line_data[] = 'Source Url';
	$line_data[] = 'Transaction Id';
	$line_data[] = 'Payment Amount';
	$line_data[] = 'Payment Date';
	$line_data[] = 'Payment Status';
	$line_data[] = 'Post Id';
	$line_data[] = 'User Agent';
	$line_data[] = 'User IP';
	
	$_grp_data[] = '"' . implode('","', $line_data) . '"';
			
	
	$search_criteria               = array();
	$start_date                    = date( 'Y-m-d', strtotime('-31 days') );
	$end_date                      = date( 'Y-m-d', time() );
	$search_criteria['start_date'] = $start_date;
	$search_criteria['end_date']   = $end_date;
	  
	$results = GFAPI::get_entries($form_id, $search_criteria );
	
	foreach($results as $rs){
		$line_data = [];
		foreach($fields as $fld){
			$line_data[] = $rs[$fld[0]] ?? '';
		}
		//data for you form
		$line_data[] = $rs['created_by'] ?? '';
		$line_data[] = $rs['id'] ?? '';
		$line_data[] = $rs['date_created'] ?? '';
		$line_data[] = $rs['date_updated'] ?? '';
		$line_data[] = $rs['source_url'] ?? '';
		$line_data[] = $rs['transaction_id'] ?? '';
		$line_data[] = $rs['payment_amount'] ?? '';
		$line_data[] = $rs['payment_date'] ?? '';
		$line_data[] = $rs['payment_status'] ?? '';
		$line_data[] = $rs['post_id'] ?? '';
		$line_data[] = $rs['user_agent'] ?? '';
		$line_data[] = $rs['ip'] ?? '';
		
		$_grp_data[] = '"' . implode('","', $line_data) . '"';
	}
	
	$uploads = wp_upload_dir();
	
	$_loc_file = $uploads['basedir'] . '/gf-'. $form_id .'-entries-' . strtotime('now') . '.csv';
	file_put_contents($_loc_file, implode(PHP_EOL, $_grp_data));
	
	//$attachments = array(ABSPATH . '/uploads/abc.png');
	$attachments = array($_loc_file);
	wp_mail($send_to, 'Gravity From #' . $form_id . ' Entries Last 30 days!', 'See attached for the exported entries from gravity form # ' . $form_id, [], $attachments);
	
	@unlink($_loc_file);
	
	echo 'Sent!';
	
    wp_die();
}
//dangerous use for tsting
add_action( 'wp_ajax_nopriv_gfexport', 'export_gf_entries');

add_action( 'wp_ajax_gfexport', 'export_gf_entries');