Logging time requires the Work on Issues permission for the Jira project to which the issue belongs.
My Work is your home base for Tempo Timesheets. You can log time in different ways, as well as plan time here.
You can:
Hover over the + then click the Log Time button at the top of a day - see below.
Click the checkmark icon on activity cards (or click the card itself) from your tracked Jira and VS Code activities, or calendar events from your Google or Office 365 Calendar - see Logging Time to Your Activities
Click the Log Activities button at the top of a day to log time to all the valid activity cards at once with a single click - see Logging Time to Your Activities
Drag a time slot on a day in the Calendar view - see below.
Drag and drop issues from the Issues side panel to a day in the List or Calendar view - see below.
Click the checkmark icon on plan cards (or click the card itself) to log time to plans you have created.
To open My Work:
Select My Work 
in the sidebar and make sure Calendar or List is selected in the upper-right.
Log Time on a Day in the List or Calendar View
You can log time quickly in the List view, which is displayed by default when you open My Work:
Click List or Calendar in the top-right to switch to that view.
Hover over the + button at the top of any day, then click the Log Time button that appears.
Fill in the Log Time form, and click Log Time when you're done.
A worklog is created for this Jira issue on this date.
To edit the worklog, click the checkmark icon on its card (or click the card itself) and make changes in the Edit Time Record form.
Log Time on a Day in the Calendar View
You can log time in the Calendar view of My Work, which displays your week as a calendar or agenda.
Click Calendar in the top-right to switch to this view.
Click the start time on a day where you want to log time, and drag to the end time.
You can also click on the time where the time record should start.
Fill in the Log Time form, and click Log Time when you're done.
A worklog is created for this Jira issue on this date.
To edit the worklog, click the checkmark icon on its card (or click the card itself) and make changes in the Edit Time Record form.
Drag Issues from the Side Panel
The Issues side panel on the right side of My Work contains issues organized by type (from predefined JQL searches). You can customize the Issues side panel to show the issues most relevant to you - see Customizing what's in the issue picker.
By default, the Issues side panel is collapsed, but Tempo remembers the last state and will display it as it was stored with your preferences. See Finding Issues with the Issue Picker for more information.
Expand the Issues side panel by clicking the arrow < in the middle of the right border of My Work. This is available in both the Calendar or List views.
Use the tabs at the top (such as Recent, Favorite, or Assigned) to select what you want to view in the panel. You can also use the Search box to search for the issue.
When you have found the issue you want to log time on, drag it to the day you want.
Fill in the Log Time form that appears, and click Log Time when you're done.
A worklog is created for this Jira issue on this date.
To edit the worklog, click the checkmark icon on its card (or click the card itself) and make changes in the Edit Time Record form.