New here, relative path problem, newbie asking for advice

Question

In PHP, you cannot reference upper-level directory files, that is, ../test/test.php or ../test.php and similar paths are No such file or directory

Answer 1

It can be quoted. Your path is wrong. Check it.

Answer 2

It can be quoted, your path is wrong, please check it

Answer 3

is an action in html and cannot be quoted