Copy the configuration below Please not this is a Example this will not work likely if u just replace the ips as your enp34s0/vmbr1 will be diffrent :
BEST TO WORK OFF YOUR DEFULT and back it UP AND Seek help via proxmox docs if this exmaple dont work :
auto lo
iface lo inet loopback
auto enp34s0
iface enp34s0 inet manual
auto vmbr0
iface vmbr0 inet static
address 90.247.138.111
netmask 255.255.255.0
gateway 90.247.138.1
bridge-ports enp34s0
bridge-stp off
bridge-fd 0
# Copy the configuration for a new vmbr1 with a different IP address
auto vmbr1
iface vmbr1 inet static
address 90.247.138.112
netmask 255.255.255.0
gateway 90.247.138.1
bridge-ports enp34s0
bridge-stp off
bridge-fd 0
# Add more addresses as needed
# auto vmbr2
# iface vmbr2 inet static
# address 90.247.138.113
# netmask 255.255.255.0
# gateway 90.247.138.1
# bridge-ports enp34s0
# bridge-stp off
# bridge-fd 0
# Continue with the rest of your configuration for other interfaces or settings