Swift: Link an identity to a user
- The Enable Manual Linking option must be enabled from your project's authentication settings.
 
- The user needs to be signed in to call 
linkIdentity(). 
- If the candidate identity is already linked to the existing user or another user, 
linkIdentity() will fail. 
Examples
Link an identity to a user
try await supabase.auth.linkIdentity(provider: provider)
Link an identity to a user with custom URL opening logic
try await supabase.auth.linkIdentity(provider: provider) { url in
  // custom URL opening logic
}