If you want to merge the contacts saved on your Android device with those in your Gmail account, there is an easy method.
Step 1. Open your device's Settings
This is an application that most often looks like a gear (⚙️) or contains cursors.
Step 2. Scroll down and tap Accounts
This option can be found in the section Staff menu.
Step 3. Select Google
The accounts are listed in alphabetical order.
Step 4. Slide the Contacts slider to the On (right) position
It will turn blue-green. Your Gmail contacts will then be synchronized with your Android contacts.
Step 5. Click on the other Google options you want to sync
Among the options offered, you will find: Agenda, Pictures, and Music.