TL;DR: To log in to the MT5 Trading Terminal, access the FundedNext Client Dashboard, go to the Trading Platform section, and enter your account credentials. Once submitted, instant access to the MT5 trading account is granted.
In order to log into your trading account on the new MT5 trading terminal:
Step 1: Log into your FundedNext Client Dashboard.
Step 2: Once you're logged in, navigate to the Trading Platform section.
Step 3: From there, simply input your account credentials, and you'll be granted immediate access to your trading account.
Please find a visual representation of the process in the video below for your reference: