purchase option groups aren't available

[appdev2023]

steps causing the problem with shopify selling plans (purchase options):

1. I created a plan and attached it to a product via graphql (no errors).

2. I see the plan on the product via the shop admin

3. I add the liquid to show the plan(s)

4. I go to the public product page and the plans shows an empty list (empty array). 

attempted resolutions:

1. tried using the cart add ajax api to attach the selling plan when adding to cart. the cart receives the selling_plan and adds the product line item (no error response), but the response doesn't have selling plan allocation.

2. set purchase option required (via admin). the product adds to cart and shows the price, but the total is always $0, regardless of the plan.

is there a bug here? any idea what i could do to resolve?

[appdev2023]

additional attempted resolution: various modifications of `appId and `merchantCode` in case there was a hidden permission issue. However neither of these appears to make any difference.

[appdev2023 · Accepted solution]

Resolved on my own.

https://shopify.dev/docs/themes/pricing-payments/purchase-options

has a little note that says merchants must meet eligibility requirements, which links to this:

https://help.shopify.com/en/manual/products/purchase-options/subscriptions/setup#eligibility-require...

Only there does it say that you MUST have Shopify payments enabled. Turned on Shopify payments in the development store and everything started working instantly.

Wish there had been some indication/error/feedback so I didn't have to spend so long needlessly hunting. Could have easily returned a graphql error when trying to create the plans.