Telegram Account Hacked and Unknown Device Connected

I am writing because my Telegram account appears to have been hacked and I was logged out of my phone while another unknown device is shown as connected to my account. Two‑step verification is already turned on, but despite this security measure I am worried that someone else still has access to my account. I do not know exactly when this started, but I noticed that I was suddenly logged out and saw another device in my account sessions. I kindly request that you urgently review my account, remove all unknown or unauthorized devices, secure the account, and give me back full access to my Telegram account.