The only option to add your order that you placed as a guest under your account is to create an account under the same email you used for that specific order. If you already have an existing account and place your order under the account email as a guest, your order will automatically appear in your account order history.
You can check your order history by following these steps:
- Create an account and log in.
- Click on "Account" in the upper toolbar
- Go to "My orders"
If you used a different email for your guest order than you have for your user account, we, unfortunately, cannot manually add the order under your user account.