Errors when trying to build the app.

[Andrei-Nitu]

Hello,

I am trying to make a similar app, that takes my heartbeat and sends the data to a server, and as I'm still learning android I'm trying to use your app as a base. However, when I try to build and run, it gives me these errors:

I know it's an old post, but can you please help me?
Kind regards,
Andrei