so I have a backup of redash (filename.gz) on my local computer, how can I use this to restore redash on my new AWS EC2 instance, there is no documentation on this. Any help will be deeply appreciated, as I was looking for a solution whole day today.

I used this doc to install my AWS: https://redash.io/help/open-source/setup#other

If the backup file was created with pg_dump, you should look for instructions on how to restore a Postgres database backup. It’s best if the Redash version you restore to is the same as the one you took backup from. Otherwise, after restoring the database, you will need to apply migrations.