This means they need to be put into pairing/discovery mode.
This is usually very easy to do, but how it works differs between brands and models.
On a Pixel, openSettings>Connected devices>Connection preferences.

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On most Samsung phones, go toSettings>Connections.
TapBluetooth>Pair new deviceon a Pixel, or chooseBluetoothon a Galaxy gadget.
TheBluetoothtoggle must be switched to the on position for this to work.

Open theSettingsapp and tapBluetooth.
Tap the earbuds when the phone locates them.
Don’t see them?Ensure that Bluetooth is onit’s indicated by a toggle at the top.

If you see a prompt to confirm, tapPair.