@Johnzen wrote:
I just want to ask, my boss avail a 3TB storage for work purposes and added me in his team so that I can also use the storage but in my account it says that i need to upgrade because i used all the storage available for me which is only 2gb.
You were likely added to a shared folder, and shared folders take up space in your account. You're accessing a copy of the folder that exists in your account. You're not accessing his account directly.
Now if your boss has a Business team with an available license, he can invite you to join the team. Doing so would allow you to merge your account into his, using one of his licenses, and you would get access to the team space. This is not the same from simply being invited to join a shared folder.