Try the following:
In your Shopify admin navigate to Online Store > Themes > Actions > Edit Code
In the "Search files..." box on that page type in "login" and a file should show up named "customers/login.liquid" or something similar. Click on and search in that file for the typo "bellow" and if it shows up replace it with "below" and then click "Save."
If the typo isn't there navigate back to Online Store > Themes > Customize and see if there are any settings in there where the typo might appear.
If neither of those options fix your problem I would reach out to the theme developer here.