Linked accounts
Open Settings → Account → Linked accounts.
This page shows connected sign-in services. Click Add VK, Add Google or Add Telegram for an available service and complete authorization in the window that opens. The connected account appears in the list after success.

Disconnect opens a confirmation for an existing connection. Make sure you retain a working sign-in method before disconnecting. An account-already-in-use message means the connection did not complete; check which user is signed into the external service.
Linked accounts provide access to your StreamVi account. A streaming destination is connected separately through Add channel.