Redirects the domain alias to another site

Hi,
I have created an alias smidl.web01.smidlonline.cz for the domain smidl.online. The domain smidl.online is not redirected to my nameservers yet. After loading https://smidl.web01.smidlonline.cz/wp-admin/ I will get the message ERR_CERT_COMMON_NAME_INVALID with another domain name ctyrnohysvet.cz. After clicking that I still want to go to the page, I am redirected to another website - ctyrnohysvet.cz. Where could the problem be?
ctyrnohysvet.cz.

ctyrnohysvet.cz. is a site created in ispconfig

 

Read https://www.howtoforge.com/community/threads/please-read-before-posting.58408/
Follow instructions.
There is FAQ on website B showing when going to A.

 

Is this WPMU? My preference would be to use alias domain with vhost so that each domain / subdomain can have their own LE certs.

But I also read that you can also do the same without vhost i.e. with only one master LE certs which covers up to max 100 domains / subdomains.

I never got the later to work with my nginx web server so I sticked to my preference.

For your problem, I guess you just have to make sure the other domain / subdomain is included in the master domain LE certs so you won't have the said error(s).

 

I'm sorry, but even after reading the instructions, I don't know what's wrong. I have three domains registered.
First domain (DNS to my servers)


Second domain (DNS to my servers)


Third domain (DNS is not on my servers)


Alias (main domain: smidl.online)


I use Nginx
Is there any setting that is wrong?
My goal is to get an alias for a domain that is not yet redirected.

Thank you for your help

 

It works. Thank you so much for your help.