To allow respondents to give some other answer than those mentioned in the options, the ‘Other’ option feature can be used.
This option can be enabled when you have selected the Multi-choice Question type:
-> Checkbox -> Dropdown list -> Radio Button -> Multi Select List
Tick the Add other option textbox to add an extra blank field along with the answer choices.
You can also change the Label as per Survey to match the question.
Survey Preview (Front End View) of “Add Other option textbox”