diff --git a/src/core/DigitalData.MessagingService.Application/OAuth2/Queries/GetOAuth2AuthorizationUrlQuery.cs b/src/core/DigitalData.MessagingService.Application/OAuth2/Queries/GetOAuth2AuthorizationUrlQuery.cs
index c07d760..6dadbce 100644
--- a/src/core/DigitalData.MessagingService.Application/OAuth2/Queries/GetOAuth2AuthorizationUrlQuery.cs
+++ b/src/core/DigitalData.MessagingService.Application/OAuth2/Queries/GetOAuth2AuthorizationUrlQuery.cs
@@ -17,7 +17,7 @@ public record GetOAuth2AuthorizationUrlQuery : IRequest<string>
     /// <summary>
     /// ID of the email account to authorize.
     /// </summary>
-    public required int AccountId { get; init; }
+    public required string Username { get; init; }
 
     /// <summary>
     /// The redirect URI registered with the OAuth2 provider.
@@ -32,8 +32,8 @@ public class GetOAuth2AuthorizationUrlQueryHandler(
 {
     public async Task<string> Handle(GetOAuth2AuthorizationUrlQuery request, CancellationToken cancellationToken)
     {
-        var account = await Repo.GetByIdAsync(request.AccountId, cancellationToken)
-            ?? throw new NotFoundException($"No email account found with Id: {request.AccountId}.");
+        var account = await Repo.FindFirstAsync(e => e.Username == request.Username, cancellationToken)
+            ?? throw new NotFoundException($"No email account found with username: {request.Username}.");
 
         if (account.OAuth2Provider == OAuth2Provider.None)
             throw new BadRequestException(