[LICENSE] Add SPDX Identifier
diff --git a/scripts/generate_fill.py b/scripts/generate_fill.py
index d939cef..330482d 100755
--- a/scripts/generate_fill.py
+++ b/scripts/generate_fill.py
@@ -12,6 +12,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+# SPDX-License-Identifier: Apache-2.0
 
 #
 # generate_fill.py ---