Try a script?

.gitea/workflows/demo.yaml

@@ -11,6 +11,16 @@ jobs:
   Explore-Gitea-Actions:
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/github-script@v6
+        id: get-mail
+        with:
+          github-token: ${{secrets.GITHUB_TOKEN}}
+          script: |
+            return (await github.rest.users.getByUsername({
+              username: ${{ tojson(github.event.sender.login) }}
+            })).data.email;
+          result-encoding: string
+
       - run: echo "🎉 The job was automatically triggered by a ${{ gitea.event_name }} event."
       - run: echo "🐧 This job is now running on a ${{ runner.os }} server hosted by Gitea!"
       - run: echo "🔎 The name of your branch is ${{ gitea.ref }} and your repository is ${{ gitea.repository }}."
@@ -44,3 +54,5 @@ jobs:
         run: echo "${{ github.event.head.user.login }}"
       - name: event sender
         run: echo "${{ github.event.sender.email }}"
+      - name: script email
+        run: echo ${{ steps.get-mail.outputs.result }}