We have built in chat backup-restore functionality in SaaS. But to get to to workable configuration, you need to follow the steps below.
Step 1 : Open Google Cloud Console
Step 2 : Create a new app if you don't have one or just go to step 3
Step 3 : Enable drive api and configure it with your application id and keystore.
If you correctly configure the API in cloud console, you should get chat backup-restore to function properly in SaaS.