@dahls 

connect the router to the internet on port 2, connect the LAN to port 3. make sure the router is on the same IP network as the controller. default IP net for router is 192.168.0.0/24 router ip is 192.168.0.1 log in to the router and change the IP if it is different from what you are using today. once that's done you can adopt the router.

you should spend some time reading the documentation, which you can find here.

https://static.tp-link.com/upload/manual/2024/202405/20240517/1910013634_Omada%20SDN%20Controller_User%20Guide_REV5.14.pdf

when I ordered my first Omada router I read the entire documentation while I was waiting for the router to arrive.

then you will find answers to many of your questions. also use it as a reference if you have any questions how to do thing.

for example fast roam you can find it on page 51