The content should be visible in-game.
Double check and see what was included in the add-on and find it in game.
You can also find the game in your library and scroll down to see additional content that you might have bought or can buy.
@Aliem Where did you purchase the add-on?
I bought it from the mobile but in chrome putting the pc mode
@Aliem Did you purchase through the Stadia store or somewhere else? Can you tell me which add-on you purchased?
If I am getting it right.
It was bought on a phone using Chrome app in desktop mode.
Not really helpful.
But if it was bought on Stadia and the core game is there, the content will be visible in-game.
The content should be visible in-game.
Double check and see what was included in the add-on and find it in game.
You can also find the game in your library and scroll down to see additional content that you might have bought or can buy.