Here's what you can do:
You can prepopulate the State/Province field using the URL in the iframe code.
For example, this is your iframe code embedded on your website:
So every time your web page loads together with the form, the State/Province field is prepopulated.
You can use this guide as your reference: Prepopulating-fields-to-your-JotForm-via-URL-parameters
After doing the instructions above, you can add this CSS code to your form using this guide:
position: relative !important;
z-index: -1 !important;
This will make Form submitters unable to click the State/Province field. However, they can still go to that field if they use the "Tab" key from their computer keyboards.
I hope this helps. If you have any further questions please feel free to let us know and we will be glad to help you. Thank you.