Unable to see and download file from Owncloud over internet

Hi! I upload files to Owncloud (local storage). Then is created public link. If i am access from local network i can see all files and download it, if i am access from Internet - i see only downloading page

#Apache access.log
10.77.0.15 - - [13/Jun/2018:14:34:09 +0300] “POST /index.php/s/iX2eBz9wIR5ix2N/authenticate HTTP/1.1” 303 982 “-” “Mozilla/5.0 (iPhone; CPU iPhone OS 11_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/11.0 Mobile/15E148 Safari/604.1”
10.77.0.15 - - [13/Jun/2018:14:34:09 +0300] “GET /index.php/s/iX2eBz9wIR5ix2N HTTP/1.1” 200 16682 “-” “Mozilla/5.0 (iPhone; CPU iPhone OS 11_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/11.0 Mobile/15E148 Safari/604.1”
10.77.0.15 - - [13/Jun/2018:14:34:09 +0300] “GET /index.php/core/js/oc.js?v=ca4fdaa73d3ae437b6ce86ab5ce09447 HTTP/1.1” 200 4810 “-” “Mozilla/5.0 (iPhone; CPU iPhone OS 11_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/11.0 Mobile/15E148 Safari/604.1”
10.77.0.15 - domain\iX2eBz9wIR5ix2N [13/Jun/2018:14:34:09 +0300] “PROPFIND /public.php/webdav/ HTTP/1.1” 401 1130 “-” “Mozilla/5.0 (iPhone; CPU iPhone OS 11_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/11.0 Mobile/15E148 Safari/604.1”
10.77.0.15 - - [13/Jun/2018:14:34:13 +0300] “GET /ocs/v2.php/apps/notifications/api/v1/notifications?format=json HTTP/1.1” 200 1127 “-” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:60.0) Gecko/20100101 Firefox/60.0”
10.77.0.15 - - [13/Jun/2018:14:34:21 +0300] “GET /index.php/s/iX2eBz9wIR5ix2N HTTP/1.1” 200 16827 “-” “Mozilla/5.0 (iPhone; CPU iPhone OS 11_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/11.0 Mobile/15E148 Safari/604.1”
10.77.0.15 - - [13/Jun/2018:14:34:21 +0300] “GET /index.php/core/js/oc.js?v=ca4fdaa73d3ae437b6ce86ab5ce09447 HTTP/1.1” 200 4955 “-” “Mozilla/5.0 (iPhone; CPU iPhone OS 11_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/11.0 Mobile/15E148 Safari/604.1”
10.77.0.15 - - [13/Jun/2018:14:34:21 +0300] “GET /index.php/core/js/oc.js?v=ca4fdaa73d3ae437b6ce86ab5ce09447 HTTP/1.1” 200 4810 “-” “Mozilla/5.0 (iPhone; CPU iPhone OS 11_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/11.0 Mobile/15E148 Safari/604.1”
10.77.0.15 - domain\iX2eBz9wIR5ix2N [13/Jun/2018:14:34:21 +0300] “PROPFIND /public.php/webdav/ HTTP/1.1” 401 1130 “-” “Mozilla/5.0 (iPhone; CPU iPhone OS 11_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/11.0 Mobile/15E148 Safari/604.1”

Server configuration
Operating system: Ubuntu 16.04
Web server: Apache 2.4.18
Database: 10.0.34-MariaDB
PHP version: 7.0
ownCloud version (see ownCloud admin page): 10.0.8.5