I am trying to set up a login and signup page for a website I am working on. I am using the APACHE 2 server and MYSQL database in Ubuntu. I wrote the HTML and PHP code in separate files, creating four files. Now when I open signup.HTML and fill in the credentials and click signup, it is open the signup.PHP file in the text editor rather than executing the code. I have already tried to go through the Apache error log, activated PHP 8.1 module and checked for any syntax error. Especially in the error log there are no PHP related problem what-so-ever. What may I do in this peculiar situation?