Backup on android
1. On the main interface of the app, there will be three points on the right side. Tap on them.
2. Go to Settings then go to Chat & Calls or Chat. Now tap on chat backups. Here you will find the option to set up Google Drive. On this page, Google Drive settings will appear at the bottom.
3. Tap Backup to Google Drive. You can set backup time here. You will never have options like Daily, Daily, Weekly and Monthly. Choose the everyday that will be better.
4. Then tap on 'Chose N Account'. Here you can decide which Whatsapp app is backed up on the Gmail ID.
5. The first option will be the mail id that is used to install Android device. If you want, you can also use a different email ID. You have to tap on the add account for this. And also have to follow the instructions that appear.
6. Now you can decide on which type of backup you would like to create on the Internet. Just on Wi-Fi, or on Wi-Fi + Cellular

Click here for detail
1. On the main interface of the app, there will be three points on the right side. Tap on them.
2. Go to Settings then go to Chat & Calls or Chat. Now tap on chat backups. Here you will find the option to set up Google Drive. On this page, Google Drive settings will appear at the bottom.
3. Tap Backup to Google Drive. You can set backup time here. You will never have options like Daily, Daily, Weekly and Monthly. Choose the everyday that will be better.
4. Then tap on 'Chose N Account'. Here you can decide which Whatsapp app is backed up on the Gmail ID.
5. The first option will be the mail id that is used to install Android device. If you want, you can also use a different email ID. You have to tap on the add account for this. And also have to follow the instructions that appear.
6. Now you can decide on which type of backup you would like to create on the Internet. Just on Wi-Fi, or on Wi-Fi + Cellular

Click here for detail