How or where to configure the interface IP?

Question

linux

I'm a teapot and I can't figure out what method is used to set the IP address? Here it is precisely clear that through DHCP, but where is this parameter set?
I want to make a receipt via DHCP and set a static IP address in parallel.

[email protected]:~# ifconfig
eth0      Link encap:Ethernet  HWaddr 02:81:4d:8d:c9:64
          inet addr:192.168.255.133  Bcast:192.168.255.255  Mask:255.255.255.0
          inet6 addr: fe80::d313:db8f:fd33:84d9/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:5032 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1945 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:4707378 (4.7 MB)  TX bytes:379238 (379.2 KB)
          Interrupt:40

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:98 errors:0 dropped:0 overruns:0 frame:0
          TX packets:98 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:7906 (7.9 KB)  TX bytes:7906 (7.9 KB)

[email protected]:~# cat /etc/NetworkManager/NetworkManager.conf
[main]
plugins=ifupdown,keyfile,ofono
dns=dnsmasq

[ifupdown]
managed=false
[email protected]:~# cat /etc/network/interfaces
auto lo
iface lo inet loopback
[email protected]:~# arch
armv7l
[email protected]:~#

Answer 1

In the instructions at your own link, they talk about the `nmcli` and `nmtui` programs. They set up NetworkManager.
The configuration information itself is stored in `/etc/NetworkManager/system-connections`.

Answer 2

/etc/network/interfaces