Suggestion:

Instead turning off the autofill on the chrome, just start typing the value on the field. When the focus in the field, the filled text will be still selected. This is the default behaviour of the autofill function.

But, if you still want to turn off the autofill, follow the below steps.

1. Open the settings on the chrome.
2. Click on search and type the turm autofill.
3. Wait for the results to be loaded.
4. By pressing tab key now, you can see few of the links like, passwords, payment methods, and addresses and more.
5. For instance, if you want to turnoff the address to be filled, just turn off the button which says “ Save and fill addresses Toggle button”

Hope it helps.