If you want to twitch activate on PS4, PS5 or PS3 just follow the steps given below:
Open the PlayStation Store and install Twitch on your PS5, PS4 or PS3.
Once the installation is complete, open the Twitch app and select Connect.
Go to twitch.tv/activate using your smartphone or laptop and make sure you're signed in to your Twitch account.
Enter the code that appears on your Twitch app on PlayStation.
Select OK and watch or stream the content.