How to develop safely in php?

Question

PHP

I develop on the laravel framework, other programmers worked on the project before, all the code was almost rewritten. But now I'm worried: are there any holes in the code, is it really impossible to skip sql injections. I'm worried, because I fixed everything that I found myself (there were gross mistakes!), But there is probably something else. Perhaps I did not see or do not understand myself that this is bad code.
Is there some kind of software that runs all the code and gives recommendations regarding everything that can be harmful from intruders? Maybe Laravel has some tools? At least check the base.
Or what are the solutions for this, if not through software?

Answer 1

Or what are the solutions for this, if not through software?

Hire a pentester