It is so simple and tricky :)
google chrome basically search for every first visible password element inside the , and tags to enable auto refill for them, so to disable this you need to add a dummy password element as the following:
if your password element inside a tag you need to put the dummy element as the first element in your form immediately after open tag
if your password element not inside a tag put the dummy element as the first element in your html page immediately after open tag
You need to hide the dummy element without using css display:none so basically use the following as a dummy password element.