Schedule a Particular task on every Friday in android Studio Java Work Manager API

I am using workmanager to send sms at every Friday for reminder purpose. even, app is closed state also. sample:

PeriodicWorkRequest periodicWork = new 
    PeriodicWorkRequest.Builder(MyWorker.class, 7, TimeUnit.DAYS).build();
WorkManager.getInstance().enqueue(periodicWork);

can anyone help on this. Thanks.

Note: I have this onetime request. its working fine. even, app is closed also.

WorkManager workManager = WorkManager.getInstance();
workManager.enqueue(new OneTimeWorkRequest.Builder(MyWorker.class).build());

If suppose, workmanager is not possible, please suggest any other api also in android.

Already Refereed this link also: its not working. Schedule a work on a specific time with WorkManager

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