Editor extension collections with single handle

[Andydrei]

Hi all!!!

I am working on some tests just for fun and noticed a strange thing in
Editor extension collections.

Using this deep link to send the merchant to the checkout and scrolling to my app (as in this tutorial)

open(`extension:checkout-block-collection?checkoutProfileId=${checkoutProfile}`, "_blank")

PROBLEM

To create an Editor extension collection the toml file needs at least 2 extensions of type customer account UI or checkout UI extensions.

DOUBTS

How is it possible to add only one extension as the app Shopify Checkout Blocks into the thank you page ?

Solutions tried already

1. Empty handle/includes

[[extensions.include]]
handle=""

Error: editor extension collection: Add extension with handle '' to local app. Local app must include extension with handle ''

2. Adding the same extension into the includes
   It duplicates the extension into the thank you

includes=["block-one-handle", "block-one-handle"]

Does anyone have any idea on how to work with this?

[AMaL]

The editor extension collection must contain two or more extensions. Single extensions not support.

Limitations:

1. Currently, can only contain customer account UI and checkout UI extensions.
2. Must contain two or more extensions.

[Jesse_Hoffman]

Are you testing on a Plus account shop? If not, you will be limited on what available extension targets you have access to.

[Andydrei]

Thank you all for your quick responses!

This isn’t about targets—it’s about a strange limitation with Editor Extension Collections, and how the Shopify Blocks app somehow bypasses this limitation.

Has anyone found a workaround?

The errors only appear when I deploy, not when I build.

My workaround was to add the same handle twice—which technically works but causes duplication.

Would love to hear if anyone has a better solution!