diff --git a/src/js/client.js b/src/js/client.js
index f6685d588..650c42e04 100644
--- a/src/js/client.js
+++ b/src/js/client.js
@@ -632,7 +632,8 @@ angular.module('Application').service('Client', ['$http', '$interval', '$timeout
             cert: config.cert,
             key: config.key,
             sso: config.sso,
-            overwriteDns: config.overwriteDns
+            overwriteDns: config.overwriteDns,
+            upstreamUri: config.upstreamUri
         };
 
         post('/api/v1/apps/install', data, null, function (error, data, status) {
diff --git a/src/views/appstore.html b/src/views/appstore.html
index 52be7a23f..8530ffb11 100644
--- a/src/views/appstore.html
+++ b/src/views/appstore.html
@@ -84,6 +84,11 @@
               </ng-form>
             </div>
 
+            <div class="form-group" ng-show="isProxyApp(appInstall.app)">
+              <label class="control-label" for="appInstallUpstreamUriInput">Upstream URI</label>
+              <input type="text" class="form-control" ng-model="appInstall.upstreamUri" id="appInstallUpstreamUriInput" name="upstreamUri" ng-required="isProxyApp(appInstall.app)">
+            </div>
+
             <div class="form-group" ng-show="appInstall.app.manifest.addons.email">
               <label class="control-label">{{ 'appstore.installDialog.userManagement' | tr }}</label>
               <p>{{ 'appstore.installDialog.userManagementMailbox' | tr }}
diff --git a/src/views/appstore.js b/src/views/appstore.js
index a893f7e6d..7556427af 100644
--- a/src/views/appstore.js
+++ b/src/views/appstore.js
@@ -88,6 +88,12 @@ angular.module('Application').controller('AppStoreController', ['$scope', '$tran
         return categoryLabel;
     };
 
+    $scope.isProxyApp = function (app) {
+        if (!app) return false;
+
+        return app.id === 'io.cloudron.builtin.appproxy';
+    };
+
     $scope.userManagementFilterOptions = [
         { id: '', icon: '', label: $translate.instant('appstore.ssofilter.all') },
         { id: 'sso', icon: 'fas fa-user', label: $translate.instant('apps.auth.sso') },
@@ -124,6 +130,7 @@ angular.module('Application').controller('AppStoreController', ['$scope', '$tran
         customAuth: false,
         optionalSso: false,
         subscriptionErrorMesssage: '',
+        upstreamUri: '',
 
         isAccessRestrictionValid: function () {
             var tmp = $scope.appInstall.accessRestriction;
@@ -149,6 +156,7 @@ angular.module('Application').controller('AppStoreController', ['$scope', '$tran
             $scope.appInstall.optionalSso = false;
             $scope.appInstall.customAuth = false;
             $scope.appInstall.subscriptionErrorMesssage = '';
+            $scope.appInstall.upstreamUri = '';
 
             $('#collapseInstallForm').collapse('hide');
             $('#collapseResourceConstraint').collapse('hide');
@@ -266,7 +274,8 @@ angular.module('Application').controller('AppStoreController', ['$scope', '$tran
                 accessRestriction: finalAccessRestriction,
                 cert: $scope.appInstall.certificateFile,
                 key: $scope.appInstall.keyFile,
-                sso: !$scope.appInstall.optionalSso ? undefined : ($scope.appInstall.accessRestrictionOption !== 'nosso')
+                sso: !$scope.appInstall.optionalSso ? undefined : ($scope.appInstall.accessRestrictionOption !== 'nosso'),
+                upstreamUri: $scope.appInstall.upstreamUri
             };
 
             var domains = [];