Azure Bot service, created using Bot SDK, not working

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":

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": "https://schema.management.azure.com/schemas/2019-04-01/deploymentParameters.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": "https://schema.management.azure.com/schemas/2019-04-01/deploymentParameters.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "azureBotId": {
      "value": "testbotclibotidmultitenant"
    },
    "azureBotSku": {
      "value": "S1"
    },
    "azureBotRegion": {
      "value": "global"
    },
    "botEndpoint": {
      "value": "https://testbotcliappservicemultitenant.azurewebsites.net/api/messages"
    },
    "appType": {
      "value": "MultiTenant"
    },
    "appId": {
      "value": "99...9"
    },
    "UMSIName": {
      "value": ""
    },
    "UMSIResourceGroupName": {
      "value": ""
    },
    "tenantId": {
      "value": ""
    }
  }
}

I see errors in the web chat channel

What I might be doing wrong? How do I debug the issue? This user reported same issue - Webchat test is not working in Azure bot - Microsoft Q&A

AFAIK, I am providing correct values for password I picked the value column from Bot's configuration and secrets pane and copied the value in WebApps MicrosoftAppPassword environment variable. But the bot still isn't working. I even created a new secret in Bot Service. I also tried using the secret ID instead of secret value in Bot's configuration. Please see images below. I have deleted the secrets now for security reasons.