Hi all schedule tasks are installed default with nopCommerce installation. Have you done any changes on that?
Please check you
ScheduleTask table and if it is empty you can always insert them from below script:
SET IDENTITY_INSERT [dbo].[ScheduleTask] ON
INSERT [dbo].[ScheduleTask] ([Id], [Name], [Seconds], [Type], [Enabled], [StopOnError], [LeasedByMachineName], [LeasedUntilUtc], [LastStartUtc], [LastEndUtc], [LastSuccessUtc]) VALUES (1, N'Send emails', 60, N'Nop.Services.Messages.QueuedMessagesSendTask, Nop.Services', 1, 0, NULL, NULL, NULL, NULL, NULL)
INSERT [dbo].[ScheduleTask] ([Id], [Name], [Seconds], [Type], [Enabled], [StopOnError], [LeasedByMachineName], [LeasedUntilUtc], [LastStartUtc], [LastEndUtc], [LastSuccessUtc]) VALUES (2, N'Keep alive', 300, N'Nop.Services.Common.KeepAliveTask, Nop.Services', 1, 0, NULL, NULL, NULL, NULL, NULL)
INSERT [dbo].[ScheduleTask] ([Id], [Name], [Seconds], [Type], [Enabled], [StopOnError], [LeasedByMachineName], [LeasedUntilUtc], [LastStartUtc], [LastEndUtc], [LastSuccessUtc]) VALUES (3, N'Delete guests', 600, N'Nop.Services.Customers.DeleteGuestsTask, Nop.Services', 1, 0, NULL, NULL, NULL, NULL, NULL)
INSERT [dbo].[ScheduleTask] ([Id], [Name], [Seconds], [Type], [Enabled], [StopOnError], [LeasedByMachineName], [LeasedUntilUtc], [LastStartUtc], [LastEndUtc], [LastSuccessUtc]) VALUES (4, N'Clear cache', 600, N'Nop.Services.Caching.ClearCacheTask, Nop.Services', 0, 0, NULL, NULL, NULL, NULL, NULL)
INSERT [dbo].[ScheduleTask] ([Id], [Name], [Seconds], [Type], [Enabled], [StopOnError], [LeasedByMachineName], [LeasedUntilUtc], [LastStartUtc], [LastEndUtc], [LastSuccessUtc]) VALUES (5, N'Clear log', 3600, N'Nop.Services.Logging.ClearLogTask, Nop.Services', 0, 0, NULL, NULL, NULL, NULL, NULL)
INSERT [dbo].[ScheduleTask] ([Id], [Name], [Seconds], [Type], [Enabled], [StopOnError], [LeasedByMachineName], [LeasedUntilUtc], [LastStartUtc], [LastEndUtc], [LastSuccessUtc]) VALUES (6, N'Update currency exchange rates', 3600, N'Nop.Services.Directory.UpdateExchangeRateTask, Nop.Services', 1, 0, NULL, NULL, NULL, NULL, NULL)
SET IDENTITY_INSERT [dbo].[ScheduleTask] OFF
GO
Moreover, you can check below file for installing required data.
/Nop.Web/App_Data/Install/create_required_data.sql