Thanks for getting in touch with the Community, thanhphuongy.
 

You can add your contractors as time tracking only users. This allows them to enter their timesheets. All you need to do is enable the feature in your account settings, then assign the appropriate access rights to your users.
 

Here's how:

1. Use the Gear (⚙️) icon, then go to Account and settings.
2. Access your Advanced tab, then click the Pencil (✏️) icon to the right of Time Tracking.
3. Tick Add Service field to timesheets and/or Add Customer field to timesheets. When either of these options are turned on, your contractors who fill out timesheets can specify if activities should be billed to a customer. If necessary, you can also activate the Show billing rate to users entering time option.
4. To choose your first day of the workweek, use your drop-down menu and pick which day to begin each week.
5. Hit Save, then Done.

Now you'll be prepared to create the time tracking only users:

1. Use the Gear (⚙️) icon, then go to Manage users.
2. Click Add user and choose Time tracking only.
3. Select a vendor, enter their contact details, then hit Save.

Once you've set up all of the appropriate user profiles, they'll be able to add time from their Time Entries screen.
 

I've also included a couple detailed resources about time tracking which may come in handy moving forward:

• Turn on & set up time tracking
• How to use basic time tracking

I'll be here to help if there's any additional questions. Enjoy the rest of your day!