tm.getDeviceId() is deprecated?

getDeviceId()

Returns the unique device ID of a subscription, for example, the IMEI for GSM and the MEID for CDMA phones. Return null if device ID is not available.

This method was deprecated in API level 26.

Use (@link getImei} which returns IMEI for GSM

or (@link getMeid} which returns MEID for CDMA.

for more information read TelephonyManager

Try this to get IMEI

 @RequiresApi(api = Build.VERSION_CODES.O)
 TelephonyManager tm = (TelephonyManager)
            getSystemService(this.TELEPHONY_SERVICE);
    String imei = tm.getImei();

OR

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            String imei = telephonyMgr.getImei();
} else {
            String imei = telephonyMgr.getDeviceId();
}

Try this to get MEID

@RequiresApi(api = Build.VERSION_CODES.O)
TelephonyManager tm = (TelephonyManager)
            getSystemService(this.TELEPHONY_SERVICE);
           
    String meid=tm.getMeid();

OR

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            String meid=tm.getMeid();
}