Building a testing script for a logistics platform

We are a marketplace in Uzbekistan for logistics services where clients can find truck drivers for their freight, at the same time, drivers or logistics firms can find new loads (like Amazon Relay, DAT truckload, Uber Freight). We have ready mobile apps and a webpage. But it is not fully finished. You will need to audit the platform, correct the problems if there is, and add some additional features.
Technology used to develop platform: Flutter (mobile apps), React (website) , PHP Laravel (back-end).
The platform itself consists of following parts: Administrative panel, iOS&Android mobile app, Landing page, Web version to post loads.