Yes, there is. Follow the steps below -

Pay & Bill >> TimeSheet >> All Timesheets >> Locate the timesheet and click on the cog icon against it >> Send Approval link to Client.

Click Yes to confirm it.

A confirmation message will appear on the screen.

You can also send it from the Assignment module.

Go to the Assignment >> Progress tab. Locate the timesheet and click the envelope icon to send the timesheet for a client approval.