Add env variable

Co-authored-by: sounmind <sounmind@users.noreply.github.com>
Co-authored-by: Sehui Park <mike.sayhi@gmail.com>
Co-authored-by: Dale Seo <dale.seo@gmail.com>
Co-authored-by: hi-rachel <rachel.uiux@gmail.com>
Co-authored-by: Nayeon <nayeonkn0330@gmail.com>
Co-authored-by: Sam Lee <SamTheKorean@users.noreply.github.com>

Author: 6 people

.github/workflows/deploy.yml

@@ -13,6 +13,8 @@ permissions:
 jobs:
   build-and-deploy:
     runs-on: ubuntu-latest
+    env:
+      VITE_API_URL: https://dalestudy-chat-backend.fly.dev
     defaults:
       run:
         working-directory: ./frontend