I created an Azure Bot using the Node.js steps in the docs

The bot worked when using the emulator. In image below, the left side screen (white) is bot emulator. Right side is VS Code running the bot code (npm start step):

Then I followed the Deploy to Azure part but the bot doesn't work. I get a blank screen when I use "Test in Web Chat":

I see internal server error in the webchat channel logs

As I am using an existing resource group. I used the deployUsingExistingResourceGroup deployment scripts. I created new app service, app service plan and bot.

App deployment values

{
  "$schema": ".json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "appServiceName": {
      "value": "testbotcliappservicemultitenant"
    },
    "existingAppServicePlanName": {
      "value": ""
    },
    "existingAppServicePlanLocation": {
      "value": ""
    },
    "newAppServicePlanName": {
      "value": "testbotcliappserviceplanmultitenant"
    },
    "newAppServicePlanLocation": {
      "value": "swedencentral"
    },
    "newAppServicePlanSku": {
      "value": {
        "name": "S1",
        "tier": "Standard",
        "size": "S1",
        "family": "S",
        "capacity": 1
      }
    },
    "appType": {
      "value": "MultiTenant"
    },
    "appId": {
      "value": "99.....9"
    },
    "appSecret": {
      "value": "i..E"
    },
    "UMSIName": {
      "value": ""
    },
    "UMSIResourceGroupName": {
      "value": ""
    },
    "tenantId": {
      "value": ""
    }
  }
}

Azure Bot deployment values

{
  "$schema": ".json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "azureBotId": {
      "value": "testbotclibotidmultitenant"
    },
    "azureBotSku": {
      "value": "S1"
    },
    "azureBotRegion": {
      "value": "global"
    },
    "botEndpoint": {
      "value": ";
    },
    "appType": {
      "value": "MultiTenant"
    },
    "appId": {
      "value": "99...9"
    },
    "UMSIName": {
      "value": ""
    },
    "UMSIResourceGroupName": {
      "value": ""
    },
    "tenantId": {
      "value": ""
    }
  }
}

What I might be doing wrong? How do I debug the issue?