Forward (share) network to a bridged interface of 3 adapters

I have this network (network structure picture): I need to configure the Kylin laptop to let other clients (PC, phones) access Internet. I have 3 USB ethernet adapter (enx000ec6c5afc1, enx00e04c68009b, enx00e04ca01003) plugged in the Kylin. I want all the clients to be in the same subnet to use RPI as second gateway. I tried to bridge the 3 USB Ethernet adapters together as br-lan, and configure DHCP and iptables to it. This is my configuration: # /etc/network/interfaces auto br-lan iface br-lan inet static bridge_ports enx000ec6c5afc1 enx00e04c68009b enx00e04ca01003 address 192.168.1.1/24 # /

Question by Lee-7723 on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.