Source: Moeomu’s blog

Prelude

• Works under macOS Big Sur
• Previously it was an imperfect solution using command start, which would also lead to a series of permission problems, but now it is finally perfect

Solution

• Edit the file /Library/Preferences/Parallels/network.desktop.xml with highest privileges
• Change the value of the UseKextless field from -1 to 0

Note: This value may not be -1 for everyone, and may not be 0 for everyone, so be brave and try!