Support intro
Sorry to hear you’re facing problems 
help.nextcloud.com is for home/non-enterprise users. If you’re running a business, paid support can be accessed via portal.nextcloud.com where we can ensure your business keeps running smoothly.
In order to help you as quickly as possible, before clicking Create Topic please provide as much of the below as you can. Feel free to use a pastebin service for logs, otherwise either indent short log examples with four spaces:
example
Or for longer, use three backticks above and below the code snippet:
longer
example
here
Some or all of the below information will be requested if it isn’t supplied; for fastest response please provide as much as you can 
Nextcloud version (eg, 20.0.5): 26.1.1
Operating system and version (eg, Ubuntu 20.04): Debian 11
Apache or nginx version (eg, Apache 2.4.25): Apache 2.4.26
PHP version (eg, 7.4): 8.0
The issue you are facing:
I am trying to get my Nextcloud (no AIO, no docker) working behind Traefik. All i am getting are SSL errors, too many redirect errors.
My Domain DNS is handled by Cloudflare. My nextcloud is working fine when i use an free external IP. With a Nextcloud problem i would post the config file etc. Is that useful in this case? The problem is probably the Traefik config.
I think i need to find someone how has got Nextcloud behind Traefik running 
Is this the first time you’ve seen this error? (Y/N):
Steps to replicate it:
The output of your Nextcloud log in Admin > Logging:
PASTE HERE
The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):
Linux cloud 5.10.0-22-amd64 #1 SMP Debian 5.10.178-3 (2023-04-22) x86_64
The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.
GNU nano 5.4 config.php
'maintenance' => false,
'updater.release.channel' => 'stable',
'trusted_proxies' =>
array (
0 => '127.0.0.1',
1 => '172.16.20.250',
2 => '172.16.20.245',
3 => '::1',
4 => '185.*.*.*',
5 => '172.18.0.0/16',
6 => 'cloud.domain.nl',
),
'mail_smtpmode' => 'smtp',
'mail_sendmailmode' => 'smtp',
'theme' => '',
'twofactor_enforced' => 'false',
'twofactor_enforced_groups' =>
array (
),
'twofactor_enforced_excluded_groups' >
array (
),
'mail_smtpauth' => 1,
'mail_smtpname' => 'EMAIL@EMAIL.COM>
'mail_smtppassword' => 'PASSWORD>
'mail_smtpsecure' => 'ssl',
The output of your Apache/nginx/system log in /var/log/____:
PASTE HERE
PASTE HERE
Output errors in nextcloud.log in /var/www/ or as admin user in top right menu, filtering for errors. Use a pastebin service if necessary.
PASTE HERE