I do not have access to form settings to change the unique submission field.

I have guided to settings and form settings to change the unique submissions field but I cannot find this option. The only option settings wise I have is under my avatar which is general settings. Thanks.

Sorry for the trouble you are facing.

Please follow this walk through image which I have created in your account to show you where to find the Unique Submission option.

Hope this will help you now.

Let us know if you have any further query.