for those still searching for a backup solution of git repositories in it's own Azure DevOps organization i have extended the project initially started by @lionel-père on github adding the capability to run the backup in a yaml azure pipelines itself (the main plus is not having to worry about renewing the PAT which can have a maximum validity period of 1 year because the pipeline uses the system PAT of devops agent) with other minor improvements and fixes. You can find it here: https://github.com/tomdess/ado-repository-backup