This is what I did:
Went to Components > Seblod > Form & Content Type > Selected my form >clicked + and selected under Type Jform Category and save > added it to construction > clicked number 2 on the right > clicked on the << that is under the Live Value column selected my joomla category > then clicked 1 and hid it and saved.
Now when I go to the form and submit I thought it would show the category in article manager but it still says uncategorized. Did I do anything wrong?