A site where 1P doesn't recognize the login/pwd fields

Thanks, @pixeldroid.

You don't mention what browser you were using, so I just went to that URL (https://tap.revenue.wi.gov/mta/_/) in Chrome.

I entered fake credentials in all three fields and submitted the form. Indeed, 1Password failed to offer to save a new Login item for me.

I visited the same URL again, filled in all three fields with fake credentials, clicked the 1Password icon in the Chrome toolbar, and chose Settings > Save New Login (as described in the Save new Login article in the 1Password 4 for Windows knowledgebase). 1Password saved a Login item with all three fields correctly stored.

I visited the same URL again, and pressed Ctrl+\. 1Password filled in all three fields with the saved values and submitted the form.

I hope that helps, @pixeldroid. Please let us know if that method does not work for you.