TL,DR: If the link of distribution source contains three parts you can get via releases_getLatestByDistributionGroup directly: owner_name, app_name and distribution_group_name. the value of install_url (or download_url) key is what you need.
Taking "Plus Messenger" source as example:
https://install.appcenter.ms/users/rafalense-70ux/apps/plus-release/distribution_groups/public
owner_name: "rafalense-70ux"
app_name: "plus-release"
distribution_group_name: "public"
So the link containing latest release metadata from the distgroup would be like:
https://install.appcenter.ms/api/v0.1/apps/rafalense-70ux/plus-release/distribution_groups/public/releases/latest
Most of openapi requires a token. If you want access assets without token, beside the method mentioned above, there is also a hidden API that allows to get all "public releases" in a certain distribution group:
api/v0.1/apps/{user}/{app}/distribution_groups/{dist}/public_releases
The API returns something like this:
[
{
"id": 9,
"short_version": "1.0",
"version": "26",
"origin": "appcenter",
"uploaded_at": "2022-04-19T13:40:13.181Z",
"mandatory_update": false,
"enabled": true,
"is_external_build": false
},
]
The value of id key can be used on first api mentioned above, replace latest with the id should be enough.
This API might be similar to https://openapi.appcenter.ms/#/distribute/releases_listByDistributionGroup, while the latter needs an token to give you "not public" releases, in theory.