Board Game Arena

I had an invitation so I offered a game by selecting "Friends" for the first time.
But I do not understand what is going on now because the massage like
"It's your turn." appears every time I play.
Did I do something wrong ?

It seems like you are playing a game using the hotseat feature. It is meant to be for playing with different people in the same room but on one device. So that is why before each turn it tells the player it is their turn so that they can "take the (hot) seat in front of the computer" and click the button when they are ready, so that it does not give away possible secret info to other players.

If you want to play with friends each on your own device, then either invite each friend individually by selecting their username, or restrict to your group and send them the link of the game so that they can join.

Thank you for the comments.
All my question has resolved.