It does not appear to recognize US zipcodes. That's ok. The bigger problem is that world wide two-sided marketplaces do not start as world wide two-sided marketplaces. Instead they grow from local marketplaces.

To grow, a two sided marketplace needs to be "liquid." This means a high probability people looking for someone to do work will find someone and a high probability that people seeking to do work will find buyers.

My advice, build the project for the place where you live. Learn how to find workers. Learn how to find people needing workers. Learn how to connect them.

Then add the next town over. When that works, all the towns in the region. And so on. Good luck.