To add a script in Greasemonkey:
A pop-up opens, you can enter:
Click on OK after the completed form. A second pop-up opens. Here you enter the script:
Save with the Save button and then close the pop-up. The script is now created.
You can edit it by clicking the greasemonkey icon and then selecting Edit Script.
The list of Greasemonkey scripts appears. Click on Preferences.
Click on Edit this script.
You can now edit the script. Do not forget to click Save when you are done.