Bugsee supports both basic, personal token and OAuth when integrating with Aha!.
Basic authentication does not require any special setup on Aha! side. Just provide valid host (URL to your Aha!), username and password.
Go to Personal page of your Aha! settings.
Then in left pane switch to Developer section.
Now switch to API keys tab and click Generate API Key button.
Give it some unique name and click Generate API Key button within that dialog.
Finally, copy generated token and paste it into Personal token field in integration wizard.
Once you start the integration wizard it will redirect you to Asana website to request to grant Bugsee permissions:
Click Authorize to allow Bugsee access to your Aha!.