if you want to use Cashfree in Nexelit cms, At first you need to get your client id and client secrets , you have to setup your Cashfree gateway settings. Go to “General settings>Payment Gateway Settings > Cashfree settings”.
Go to Cashfree.com login to your dashboard. then click on Payment Gateway > Try Environment button.
you will find option to go to production mode in top right corner a button name Switch to Production
now click on developer > api
the process is same for production mode,