How to anylyze load testing of app plaform for a PHP rest API project

Hi, Before we had a droplet to serve a response to the client, now the team was quite interested to use the DO App platform and we created an app there, everything is working very well. But we need an app that can handle 5K concurrent requests at a time. We have a basic plan of $5 per month. We are having some problems/confusion to understand the depth process of the app platform. could you please solve the below queries that can make our team confident to use the app platform?

1. how many concurrent requests can handle by a $5 per month starting plan
2. It does not provide SSH access then how can I read server logs of my virtual machine. It gives me console access from the browser but does not allow me to read the logs.
3. It returns gateway timeout error on load testing but I am not able to set connection timeout params in the Nginx config file.