domain redirect

Two ways.

1) .htaccess

2) Park the domain on top of the other one.

Thank you so much for that. How do I do either of those?

For domain parking, ask your host (they have different setups often).

For .htaccess you have to buy hosting for your domain and then put this in the top of your .htaccess:

#Options +FollowSymLinks
RewriteEngine on
RewriteCond %{HTTP_HOST} ^www.olddomain.com$[OR]
RewriteCond %{HTTP_HOST} ^olddomain.com$
RewriteRule ^(.*)$ https://www.newdomain.com/$1 [R=301,L]

I tried this rewrite code, as I have the same constellation of websites and want to redirect one page (abc.com) to the WordPress installation on the other domain (a-b-c.com).
The domains both are rooted to the same directory and when I start the second domain, WordPress (with activated MultiSite) treats it as if I try to register a new blog and leads to the following URL:
https://a-b-c.com/wp-signup.php?new=abc.com
Is it possible to completely treat the WordPress start as if I had started the a-b-c.com ULR when entering abc.com?

The Rewrite-Code does not change the start of the website in my installation. The website is treated in the same way with or without the rewrite condition.
Thank you for your kind help!
RGerhart

Multisite is a WHOLE different kettle of wax, Roswitha ?? Post what you wanna do up in the Multisite Forum please.

Thank you very much for your tip. I will ask in the MultiSite forum.
Best wishes, RGerhart