1.AI Image upscaler Day Pass is online version, you can visit ai.nero.com to find it.

2.Upload a photo will go to Edit page, in here, you can click "Portrait"
icon to login account, the account is your filled Email address in Billing info page:

3.After login, you can get your day-pass credits, if not get, click "Refresh" button 

credits will shown in here after refresh. 

You can also get 5 free credits every day after click "Gift" icon.

4.Select any AI models you wanted, and click "Start" button to process AI Upscaling (One credit will be deducted for a successful upscaling)

5.Download the result photo to your local PC:

Notes: Day pass credit will count down(24h) from your login your account on-line, not your purchased time.