How can i specify channel for only two person to have video call using agora

Question

i have read a lot of agora docs but couldn't find my need .

when i need to have new agora account so i will get token and appid and channel name

now i noticed when i want to have video call so i must entry the channel name as exactly in my dashboard like following

await myEngine.joinChannel(token,'here i put the channel name that found in my dashboard ',null, 0);  

but that will make group video call to anyone use the same channel name ..

but How can I not abide by this channel name in my dashboard ? like i want my users to create local channels name on their own and share it to whoever they want so they will have video call

for example i want the user to feel free to name his channel name and share this channel name with the other person so they have video call together .

but I noticed that I was forced to use the channel name I created on my dashboard

for example user 1 create channel name then he share it to user 2so they have video call and user 2created OTHER channel name and share it with other person .... and so

i have found this link https://www.agora.io/en/blog/real-time-messaging-and-video-with-dynamic-channels-using-the-agora-flutter-sdk/

it exlain my need but suddenly it back to use the same channel name in dashboard i am really totally confused

any help .. ?