Using pug for for php pages?

Question

PHP

Help me to understand. There is a project deployed on open server - CMS. I write the html markup to the index.php file. I am using gulp to build. I recently tried PUG at work. I really liked the simplicity of the code.
Question: how to configure the gulp build so that the html from pug is generated in the index.php file? The index.php file already contains php code blocks inside. Please answer in detail, step by step if possible. What packages to include in gulp.js, etc.
Thanks in advance. Please do not throw stones at me, I was only engaged in layout and I don’t understand php well.