Which toml file did you add it to? shopify.app.toml or shopify.extension.toml?
If it doesnt show in the app backend dashboard, it seems like it’s either missing from the correct toml file, or you forgot to deploy the app with shopify app deploy.
Thanks curzey. I have applied the change to shopify.extension.toml and I have not deployed. This is in dev store (i.e., shopify app dev) so I thought permissions would be easier. Is shopify app deploy necessary?
Edit: after updating extension.toml and deploying, nothing is changed sadly. Both .toml files have access_scopes defined but shopify app deploy does nothing. I wonder if it is because of the info displayed when deploying:
New version created, but not released.
Network access must be requested and approved in order for this extension to be published
The step that I was missing was to re-install the app . Need to make sure to click install when previewing so that new changes are available. With that the request succeeds.