To manually add a grade to the Grader Report in Moodle, you can Add a Grade Item in Moodle Gradebook Setup. The graded item will act as a placeholder for your to manually add student grades.
Step 1
In Grade book Setup, Click Add Grade Item.
Step 2
Name the Grade Item and complete the setup. Click Save.
Note. Please set a maximum grade value.
Step 3
The Grade Item will appear in Gradebook Setup. You can move and adjust the Grade Item as if it were a graded activity.