I know that you can sell your bitcoin to trade plattform like coinbase etc.. BUT you need to verify your identify, so it' s not anonymously.
How do you cashout your bitcoins anonymously then?
Why do you want to cash out when you can use it for buying something? If you want to sell your btc to fiat currency such as USD, most exchanges will requiring you to submit your identity.
In my country, if i want to sell my coin to my native currency, i will have to Kyc lv2, identity documents and the selfie photo.