Go to the root folder of your project from terminal and do a build in release mode and run flutter build web You should see a build folder (/build/web) in the root directory, just copy that folder, Your application is enclosed into a main.dart.js file. Log in to your AWS Management Console. Go to Security Credentials link from the drop-down menu (username >Security Credentials) Find the Access Credentials section, and copy the latest Access Key ID. copy the Secret Access Key. Choose repo on codemagic and Go to Settings — Publish — AWS S3 Bucket Fill the Access key ID, secret access Key, and Bucket name Trigger a build created from step 1, on the success, it will be deployed to an S3 bucket