Hi ghkelso19,

Currently it’s up to extension developers to add support for the new checkout flow offered via the Cart and Checkout Blocks. We have some documentation for Third-party developers and some Developer Resources available to help with their integration efforts. (see https://github.com/woocommerce/woocommerce-blocks/tree/trunk/docs#third-party-developers).

As a merchant, the best course of action right now if you are using a plugin that isn’t working with the Cart and Checkout Blocks is to notify the developer of the extension and ask if they can add support.

I also recommend submitting a feature request for Authorize.net to support the blocks based checkout flow at this link: https://woocommerce.com/feature-requests/authorize-net/

We keep an up to date list of compatible extensions in this documentation. https://woocommerce.com/document/cart-checkout-blocks-support-status/#section-5

Please make this happen ASAP!