I've used three different APIs for this project. These are the APIs I passed on using and why:

OpenSky Network API

If I couldn't use AeroAPI, I'd use OpenSky Network API. One huge plus is that this API is open-source and free. You can acquire flight IDs, latitude and longitude, velocity, and other flight details.

One downside to using this API is that it does not provide commercial flight data such as airport schedules, delays, or similar information that cannot be derived from ADS-B data contents.

Aviationstack

This API was difficult to use and expensive. The Free Plan offers 1,000 API requests per month.

The company claims to provide live tracking flight data:

Thanks to real-time data integration with one of the most sophisticated aviation data vendors on the market, aviationstack delivers accurate flight data that you can use to build booking and tracking applications.

In contrast to the claim made by Aviationstack, my personal experience contradicts it. When I contacted their representative, I was told that I needed to upgrade my membership to a higher tier in order to access the live tracking data. Even after I opted for a monthly premium data subscription cost of $49.99, I still couldn't access the required live tracking feature.

Moreover, if you plan to use Aviationstack, please keep in mind that if you need to cancel your subscription, you will have to send an email to the company and provide them with a valid reason for doing so.

Please note that the use of Aviationstack is solely at your own discretion.