(The content may be a bit strange because it was translated by a translator.)

I want to set up 2wan through winbox, but I don't know how to check IP first.
There are two ISPs, but if you connect directly to the PC and check the IP, you will get the same IP.

After setting up a local bridge, adding its ports, IP Addresses set up local IP and any WAN IP.
Since then, DHCP settings and NAT, gateway settings have been set up, but the Internet is not working because of the randomly set WAN IP.
How can I verify the IPs of the two ISPs?

The instrument you use is RB4011.

How do you get those IPs from your ISP? Through DHCP?
Are those Private addresses? If yes just change the DHCP Pool on your ISPs Router...

How do you get those IPs from your ISP? Through DHCP?
Are those Private addresses? If yes just change the DHCP Pool on your ISPs Router...

We accept it by DHCP.
What does "change the DHCP Pool" mean?
For example, if you are assigned an ip of 192.168.0.10/24, do you mean this part of /24 to change the pool?
Does it mean that it should be modified to 192.168.10.10/25 and divided into 192.168.10.0~127/ 128~255?

I mean that if your ISP 1 gives you addresses in the range for example, 192.168.1.2-192.168.1.254
and ISP 2 again 192.168.1.2-192.168.1.254, then you must change one of them to something different, lets say 192.168.10.2-192.168.10.254

I mean that if your ISP 1 gives you addresses in the range for example, 192.168.1.2-192.168.1.254
and ISP 2 again 192.168.1.2-192.168.1.254, then you must change one of them to something different, lets say 192.168.10.2-192.168.10.254

What should I do if I am a Public addresses?

The equipment is now connected to ISP->Modem*2->Router->Other devices.

The modem is connected to ports 1 and 2 on the router, respectively, and if the router OS checks this, the number 1 and 2 are on the same network.
The first three octets are the same and the last one is different. The subnet mask is /24.
ex)ether1 IP : 113.128.225.8/24 , ether2 IP : 113.128.255.54/24

I wonder how to set up 2WAN in this case.
It doesn't matter if only port1 is plugged in, but if you connect port 2 additionally, port 1 is down and doesn't work.

If you need to separate the two networks, how can you separate them, or if you want to know the authorized address?

Even if thats the case, it will still work...
You can take a look here: https://wiki.mikrotik.com/wiki/Manual:PCC
It is an example of how to load balance 2 Wan Interfaces...

Even if thats the case, it will still work...
You can take a look here: https://wiki.mikrotik.com/wiki/Manual:PCC
It is an example of how to load balance 2 Wan Interfaces...

If you check the IP address that DHCP sprays, the network assigned by the ISP appears to be 111.123.215.xxx/24 (the IP is an example).

Even if it is an Public IP rather than a private IP, does it work if I change the network pool inside the OS to set up 2WAN?

For example, would port 1 be set to 111.123.215.10/24, port 2 to 111.123.225.20/24, and 2WAN setting work normally?

Or is proxy ARP possible with two WANs?

For example, would port 1 be set to 111.123.215.10/24, port 2 to 111.123.225.20/24, and 2WAN setting work normally?

Why not?
If you look at the example you work with interfaces, not with IPs... So ?