How to properly use bcrypt for password hashing in PHP?

Hello everyone! I'm a beginner PHP developer and I can't figure out secure password storage. Currently I'm just using the md5() or sha1() function for hashing, but I read somewhere that this is wrong and insecure. They say I need to use bcrypt.

<?php\n// My current code (I know it's bad)\n$password = 'my_secret_pass';\n$hash = md5($password);\n// Save $hash to database\n\n// Verification on login\nif (md5($_POST['password']) == $hash_from_db) {\n    echo "Successful login!";\n}\n?>

I've heard about bcrypt, but I don't understand how to install and use it. Apparently there's some built-in function in PHP, but I don't know what it's called and how to work with it properly. I'm also confused that I need to specify