Family member fired wondering what they can do

They worked in HR at a large company for over a year. They were just told in person they were fired on 5/1/23 the employers reason for firing was “inserting opinions into conversations” . They have 0 prior write ups or verbal warnings. It’s also known that the gm doesn’t like them and the gm also has an inappropriate relationship with the owner. This takes place in Minnesota any advice is appreciated 🙂