Custom App requests authentication on Teams Mobile (iOS)

Hi Sayali-MSFT,

sure, the Teams App manifest.

{
"$schema": "https://developer.microsoft.com/en-us/json-schemas/teams/v1.17/MicrosoftTeams.schema.json",
"version": "1.0.2",
"manifestVersion": "1.17",
"id": "XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX",
"name": {
"short": "EWA",
"full": "EWA - Eriks Web App"
},
"developer": {
"name": "Erik Kleefeldt",
"mpnId": "",
"websiteUrl": "https://somelegacywebappnamereplacedhere.msappproxy.net/",
"privacyUrl": "https://www.contoso.com/about/",
"termsOfUseUrl": "https://www.contoso.com/about/"
},
"description": {
"short": "EWA is designed to demo a web-based app showing up as a Teams integrated app",
"full": "Eriks Web App - EWA - Is designed to demo a web-based app showing up as a Teams integrated app"
},
"icons": {
"outline": "outline.png",
"color": "color.png"
},
"accentColor": "#FFFFFF",
"staticTabs": [
{
"entityId": "YYYYYYYY-YYYY-YYYY-YYYY-YYYYYYYYYYYY",
"name": "Web",
"contentUrl": "https://somelegacywebappnamereplacedhere.msappproxy.net/",
"websiteUrl": "https://somelegacywebappnamereplacedhere.msappproxy.net/",
"scopes": [
"personal"
],
"context": [
"personalTab"
]
},
{
"entityId": "about",
"scopes": [
"personal"
]
}
],
"validDomains": [
"somelegacywebappnamereplacedhere.msappproxy.net",
"*.msappproxy.net",
"*.contoso.com"
],
"webApplicationInfo": {
"id": "ZZZZZZZZ-ZZZZ-ZZZZ-ZZZZ-ZZZZZZZZZZZZ",
"resource": "https://somelegacywebappnamereplacedhere.msappproxy.net/user_impersonation/"
},
"configurableProperties": [
"name",
"smallImageUrl",
"largeImageUrl",
"accentColor"
]
}

The legacy web app behind is a HTML website secured behind a Entra ID app proxy (...msappproxy.net).

The HTML website itself does not require any authentication only the Entra ID app proxy seems to require pre-authentication. But this pre-authentication within Teams on iOS is not passed through.

Best Regards
Erik