SNMP Oid to get interfaces' IpAddress (MAX BR1 pro)

Hello,

I’m trying to get the ip address of interfaces (WAN, LAN and Cellular) but the iso OID dosn’t work form me.

snmpwalk -v2c **** 192.168.0.254 .1.3.6.1.2.1.4.20.1
iso…3.6.1.2.1.4.20.1 = No Such Object available on this agent at this OID.

I can’t find where to dowload the device’s mib.

Can you support me please.
Regards,