new website opens using ip4 numbers but not using name

I rented a new cloud server with IONOS, cheap.

I have set it up, and used Filezilla to upload the webpages.

I have tested all the little webpages on my laptop first. Everything works as I want, all very very simple stuff!

I have not set up ssl yet.

Let's say my public ip4 number is 123.456.789.123

If I enter http://123.456.789.123 then my webpage opens, no problem.

Let's say my webpage name is mywebpage.com

If I enter http://mywebpage.com I end up at IONOS, not my webpage. I don't understand this.

I have set up a virtual host like this:

Code:<VirtualHost *:80>
ServerName mywebpage.com
ServerAlias www.mywebpage.com
ServerAdmin webmaster@mywebpage.com
DocumentRoot /var/www/mywebpage.com/public_html

<Directory /var/www/mywebpage.com/public_html>
Options -Indexes +FollowSymLinks
AllowOverride All
Order allow,deny
allow from all
</Directory>

ErrorLog ${APACHE_LOG_DIR}/mywebpage.com-error.log
CustomLog ${APACHE_LOG_DIR}/mywebpage.com-access.log combined
#RewriteEngine on
#RewriteCond %{SERVER_NAME} =mywebpage.com [OR]
#RewriteCond %{SERVER_NAME} =www.mywebpage.com
#RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,NE,R=permanent]
</VirtualHost>I disabled the default virtual host

Code:# disable the default
sudo a2dissite 000-default.confI enabled my virtual host

Code:# enable the new virtual host
sudo a2ensite mywebpage.com.confI reloaded apache2

Code:# reload apache2
sudo systemctl reload apache2
Any tips about why the webpage name won't work, but the ip4 number works please??