You can back up your contacts to your SIM card, internal storage or Google account.
1. Go to Contacts, then tap the Circle with a letter or your profile picture menu icon at the top right of the screen.
2. Contacts app Settings > Export.
Then, do one of the following:
To export contacts to the SIM card:
Tap SIM card. Select the contact(s) and tap OK to copy the selected contact(s).
To export contacts to the internal storage:
Tap Export to .vcf file. Select the location where to save the contacts and tap SAVE.
To export contacts to your Google account:
Ensure you are logged into your account.
Tap your Google account > Export to .vcf file. Select the location where to save the contacts and tap SAVE.