Hello Milan,
Yes, that is possible.
There are small differences, depending on what exactly you want to achieve.
1) If by 'saving data to a field' you mean the following:
Use a URL parameter to populate a field on the form.
This is possible and is described in the documentation.
'Default values as URL parameters':
docs.joomla-4.visforms.vi-solutions.de/e...ue-as-url-parameter/
'Which value is finally displayed in the form?':
docs.joomla-4.visforms.vi-solutions.de/e...isplayed-in-the-form
2) If by 'saving data to a field' you mean the following:
Use a URL parameter to write it to the form's data table after submission, along with the form's other field values.
The user should not be able to see or edit the value of the URL parameter.
This works as described above.
In this case you have to work with a field of type 'hidden'.
3) If by 'saving data to a field' you mean the following:
Use a URL parameter to write it to the form's data table after submission, along with the form's other field values.
The user should be able to see the value of the URL parameter but not edit it.
This works as described above.
In this case, you must activate the 'Read-Only' checkbox parameter for the affected field in the configuration, 'Basic Options' tab.
I very much hope to have understood you correctly.
Kind regards, Ingmar