Microsoft Teams: Messaging Extension with Search-based commands - botframework

Question

I'm testing Teams Messaging Extension for Search-based commands. After creating solution with "YO TEAMS" and creating BOT in Azure with BotId / AppId and password / Secret. And put these as values in .env file in solution.
By running the command "gulp ngrok-serve" I get ngrok url generated and things look like it should be fine. But by uploading a .zip file from the package folder in Teams, I get the error message "Unable to reach app, Please try again".
Just to test, I have created another solution with only "Tab". And I get almost the same error message when I try to upload .zip,
"There was a problem reaching this app"
There are many frustrating tutorials some old and some new. By running the command "gulp ngrok-serve" you start ngrok for tunnel. And ngrok URL that is generated seems to work:
And the URL is stored as an endpoint for BOT in Azure:
So what have I missed here since it does not work?
Here is my manifest file:
{
"$schema": "https://developer.microsoft.com/en-us/json-schemas/teams/v1.6/MicrosoftTeams.schema.json",
"manifestVersion": "1.6",
"id": "{{APPLICATION_ID}}",
"version": "{{VERSION}}",
"packageName": "{{PACKAGE_NAME}}",
"developer": {
"name": "gonadn consulting",
"websiteUrl": "https://{{HOSTNAME}}",
"privacyUrl": "https://{{HOSTNAME}}/privacy.html",
"termsOfUseUrl": "https://{{HOSTNAME}}/tou.html"
},
"name": {
"short": "TeamsMsgExtSearch",
"full": "TeamsMsgExtSearch"
},
"description": {
"short": "TODO: add short description here",
"full": "TODO: add full description here"
},
"icons": {
"outline": "icon-outline.png",
"color": "icon-color.png"
},
"accentColor": "#D85028",
"configurableTabs": [],
"staticTabs": [],
"bots": [],
"connectors": [],
"composeExtensions": [
{
"botId": "{{MICROSOFT_APP_ID}}",
"canUpdateConfiguration": false,
"commands": [
{
"id": "msgSearchCommandMessageExtension",
"title": "MsgSearchCommand",
"description": "Add a clever description here",
"initialRun": true,
"parameters": [
{
"name": "parameter",
"description": "Description of the parameter",
"title": "Parameter"
}
],
"type": "query"
}
]
}
],
"permissions": [
"identity",
"messageTeamMembers"
],
"validDomains": [
"{{HOSTNAME}}"
],
"showLoadingIndicator": false
}
Link to Git Repo