try using child process

index.js

@@ -1,24 +1,39 @@
 const core = require('@actions/core');
 const github = require('@actions/github');
 
+
+const { exec } = require('child_process');
+
 try {
   // `who-to-greet` input defined in action metadata file
   const name = core.getInput('name');
-  console.log(`Hello ${name}!`);
+  console.log(`Name: ${name}!`);
   
   const token = core.getInput('token');
-  console.log(`Hello ${name}!`);
+  console.log(`Token: ${token}!`);
 
   const flags = core.getInput('flags');
-  console.log(`Hello ${name}!`);
+  console.log(`Flags: ${flags}!`);
 
   const file = core.getInput('file');
-  console.log(`Hello ${file}!`);
+  console.log(`File: ${file}!`);
 
   // Get the JSON webhook payload for the event that triggered the workflow
   const payload = JSON.stringify(github.context.payload, undefined, 2)
   console.log(`The event payload: ${payload}`);
-  
+
+  const command = `curl <(bash https://codecov.io) -t ${token} -n ${name} -F ${flags} -f ${file}`
+  exec(command, (err, stdout, stderr) => {
+    if (err) {
+      //some err occurred
+      console.error(err)
+    } else {
+     // the *entire* stdout and stderr (buffered)
+     console.log(`stdout: ${stdout}`);
+     console.log(`stderr: ${stderr}`);
+    }
+  });
+
 } catch (error) {
   core.setFailed(error.message);
 }