I have a website that requires Username, Pin code and password. How can i store those in 1Password?

First, I typed in a Client ID, a PIN and a Password and stored the information in 1Password with the help of the inline popup from 1Password in the browser. A new entry was created. But it only consists of a username, password and the URL.

Trying to fill in the credentials worked. "Client ID" and "Password" were filled correctly.

Second, I tried to create a custom field for the PIN. It is a bit difficult because you are not able to look into the HTML code of the page. I had to save the whole website. Then I searched the HTML code and created custom fields "spnPIN" and "txtPIN". But it didn't work. The PIN field was not autofilled.

Maybe it could be that the problem is the type of the field. It is the same type as the password field - "password".

Hopefully someone from 1Password is able to help here. Maybe the 1Password in the browser extension has to be adjusted to work with that specific website.