Andriod mobile app connect to sql server

I have purchased some licence already for android app. But unable to connect it to my local sql server.

Is it possible to connect android app to local SQL server?

Local? Like localDB?
App doesnt connect direct to sql it uses the message server. Check you config and firewall on server machine running message server.

No I mean SQL 2017 Express edition. My regular db that connect other terminals.

Ok. Either way app doesnt connect to sql it uses api through message server.
Think that needs sql rather than localdb but your using sql anyway.

Okay. Thank you. But I am running Sambapos already on a server. How to I configure the tablet to place order. Like terminals.?

What I am saying is that the app doesnt connect directly to sql, it uses the message server, so check the service is running and your firewall etc. You client machines can work via sql without message server so check configured for message server too.
Check the user and role set up as documentation.

https://kb.sambapos.com/en/4-45-android-caller-id-mobile-application/

Follow the steps here to get it to work. Be sure it’s connected via WiFi to your network the message server is on.

https://kb.sambapos.com/en/8-1-android-mobile-client-v2-setup/