In addition to post above let me disclose requirements to the Nextcloud config.php file specified for reverse bypass. Following rows must be added into the file

  'trusted_domains' => 
  array (
    0 => '192.168.1.4:23456',
    1 => 'allcash.asuscomm.com',
  ),

and following past in the bottom of file before );

  'trusted_proxies' => 
  array (
    0 => '192.168.1.32',
    1 => 'localhost',
    2 => 'allcash.asuscomm.com,
  ),

Also you can override route to direct all requests over DDNS and https:// adding these rows:

  'overwritehost' => 'allcash.asuscomm.com:443',
  'overwriteprotocol' => 'https',
  'overwritewebroot' => '/Nextcloud',

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Hello,

I’m coming back to you for this problem, it’s solved…
My Config in config.php is
’overwritehost’ => ‘app.***.net’,
‘overwriteprotocol’ => ‘https’,
‘overwritewebroot’ => ‘/nextcloud’,
‘overwritecondaddr’ => ‘^192.168.1.3$’,
‘overwrite.cli.url’ => ‘https://app 156.***.net/nextcloud/’,

192.168.1.3 is IP of my reverse Proxy
192.168.1.5 is IP of my Nextcloud server

Configuration of my Apache Reverse Proxy :
ProxyPass /nextcloud http://192.168.1.5/nextcloud 47
ProxyPassReverse /nextcloud http://192.168.1.5/nextcloud 47
ProxyPassReverseCookiePath /nextcloud /nextcloud

The problem is the cookie… When many sites was activated in the reverse proxy, the cookie has a bad url… So the directive ProxyPassReverseCookiePath solved my problem.

Cordially