Per default DHCP is configured. However if the raspberry works as server and has to be reached via the network a static address is desired.
From Debian 12 Bookworm Networkmanager is used and can therefore be configured using it
sudo ip a to see what is active
sudo nmtui to get the text user interface of Networkmanager. Edit a connection, select IP4 to manual and enter a manual IP4 address
Address 192.168.1.<n>/24
Gateway 192.168.1.1
DNS 8.8.8.8
disable IP6 and save it and sudo systemctl restart NetworkManager to restart it
sudo ip a to see what happened, if connected with ssh then the address remains an a sudo reboot is required
For Debian 11 Bullseye to have a static address edit sudo nano /etc/dhcpcd.conf or sudo mc
Give a static address if the raspberry works as server and will get accessed over the network. It is also possible to turn on networkmanager instead of dhcpcd and then the steps as for Debian 12 can be done.