Generate new salt and key for wordpress and replace with the old one which will
forcefully logout all the logged in users.
https://api.wordpress.org/secret-key/1.1/salt/

https://www.greengeeks.in/tutorials/article/completely-force-logout-users-wordpress/#:~:text=Using%20the%20WPForce%20Logout%20Plugin&text=Then%20in%20the%20%E2%80%9CBulk%20Actions,%E2%80%9CLogout%20All%20Users%E2%80%9D%20button.