Checking Code Chrome Extension - Implement Google Pay & Checking Server Security

i am looking for a developer for checking the code of my chrome extension ( you can check it here [login to view URL] a LinkedIn Automation Bot) and license app if there are hooks, because i am suspecting that my old developer made some mistakes or even more worse things. Then i also need to install google pay, so that user can directly pay on google web store. i need that my extension has 7 days free trial ( actually working) and a yearly payment of 99€ the year (Actually not working). Also i meed you to check if someone else acesses to my server without my consent.