Update codecov.yml

.github/workflows/codecov.yml

@@ -1,4 +1,33 @@
-- name: Upload coverage reports to Codecov
-  uses: codecov/codecov-action@v3
-  env:
-    CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
+name: Example workflow for Codecov
+on: [push]
+jobs:
+  run:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+    env:
+      OS: ${{ matrix.os }}
+      PYTHON: '3.10'
+    steps:
+    - uses: actions/checkout@master
+    - name: Setup Python
+      uses: actions/setup-python@master
+      with:
+        python-version: 3.10
+    - name: Generate coverage report
+      run: |
+        pip install pytest
+        pip install pytest-cov
+        pytest --cov=./ --cov-report=xml
+    - name: Upload coverage to Codecov
+      uses: codecov/codecov-action@v3
+      with:
+        token: ${{ secrets.CODECOV_TOKEN }}
+        directory: ./coverage/reports/
+        env_vars: OS,PYTHON
+        fail_ci_if_error: true
+        files: ./coverage1.xml,./coverage2.xml,!./cache
+        flags: unittests
+        name: codecov-umbrella
+        verbose: true