I left the team that I created myself

@mertvae - When you left the team, your content, e.g., boards, would have been assigned to a Team Admin of the team. You could ask to be added back to the team and have them make you owner of the board again, or you could ask one of the admins to set the board’s Visitor access, i.e., “Anyone with the link” to “Can view”, and then send you a link to the board. Once you have a link and can open it, you could duplicate the board to your new account. Note: if the board is not in a Free Plan team, there may be extra steps required.

Here is a post that I wrote on the topic of recovering a board: