Can I translate the 'How will you be paying today?' text?

Apple Pay

Update the 'How will you be paying today?' text in the Apple Pay section of the checkout:

1. In the merchant portal, click Storefront and select Copy & translations.
2. Click the Checkout tab and select the Payment section.
3. Locate and edit the Payment Options (Apply Pay Only).

Google Pay

At the moment, this text cannot be updated. However, future improvements to the feature will allow the Google Pay subscription disclaimer to be edited.

Shopify Checkout Integration or Migrated Shopify Checkout Integration

The checkout process and settings are managed by Shopify on the Shopify Checkout Integration. See Shopify's guide on Translating your checkout. 

If your store is on any other plan than Plus, then you can't remove or edit some text that displays on the customer checkout for orders that contain subscription purchases. See Shopify's guide on Non-editable checkout wording for subscription purchases.