To enable or disable the form autofill feature in Firefox, follow these steps:
- Open Firefox and click on the menu button (three horizontal lines) at the top-right corner.
- From the drop-down menu, select "Options" (Windows) or "Preferences" (Mac).
- In the Options or Preferences tab, click on the "Privacy & Security" option on the left-hand side.
- Scroll down to the "Forms & Autofill" section.
- To enable autofill, make sure the checkbox next to "Autofill addresses" is checked.
- To disable autofill, uncheck the checkbox next to "Autofill addresses".
You can also access autofill settings by typing "about:preferences#privacy" in the Firefox address bar.
Note: The steps may vary slightly depending on the version of Firefox you are using.