Fix.

Author: trivialfis

.github/workflows/doc.yml

@@ -54,7 +54,7 @@ jobs:
       - name: Trigger RTD
         env:
           RTD_AUTH: ${{ secrets.RTD_AUTH_TOKEN }}
-          TEST_SEC: $${ secrets.TEST_SECRET }}
+          TEST_SEC: ${{ secrets.TEST_SECRET }}
         run: |
           echo "branch name: ${BRANCH_NAME}"
           echo "token: ${#RTD_AUTH}"