OIDC connect with Shopify

⚙️Configuration🏬Self-hosted🛡️Authorization❓Question🔗OIDC

I'm trying to integrate ZITADEL with Shopify Customer Accounts (OIDC) and I'm running into an "Access token request error" after login.

Setup:

ZITADEL self-hosted

OAuth endpoints resolve correctly

Discovery document works

Login flow works and users can authenticate successfully.

Flow:

Shopify redirects user to ZITADEL authorize endpoint

User logs in successfully

ZITADEL redirects back with authorization code

Shopify attempts token exchange

Shopify returns: "Access token request error"

openid email customer-account-api:full profile

ZITADEL login logs show successful authentication:

completeFlowOrGetUrl: got OIDC/SAML flow result
Session is valid: true
Password auth: OIDC/SAML flow with requestId

So authentication succeeds, but the token exchange step fails.

Questions:

Are there specific OIDC settings required in ZITADEL for Shopify Customer Accounts?
BTW I connected with Shopify and they said that email_verifiedemail_verified claim is missing.

Does ZITADEL support the customer-account-api:full scope format expected by Shopify?

Is client_secret_post required for the token endpoint with Shopify?

If anyone has successfully integrated ZITADEL with Shopify Customer Accounts, I’d really appreciate guidance