I set up a VM on Google Compute Engine through the marketplace I chose the VM (Tomcat Tomcat (Google Click to Deploy) - Open source Java Servlet container)
With the following data:
Operational system Debian 9.11 Package Contents Apache 2.4.25 Google-Fluentd 1.6.17 OpenJDK 1.8.0 Stackdriver-Agent 5.5.2 Tomcat 8.5.14.0
I would like to know where is the tomcat (webapps) folder where I can send my application .WAR file.
The webapps folder path is actually relative to the path defined by the CATALINA_BASE environment variable, as you can see documented here.
In the Google Cloud Developer Console, when you access the external IP address assigned to your deployment, the default page reads:
Tomcat8 veterans might be pleased to learn that this system instance of Tomcat is installed with CATALINA_HOME in /usr/share/tomcat8 and CATALINA_BASE in /var/lib/tomcat8
You'll find the webapps folder at /var/lib/tomcat8/webapps.