Seeking advice: US company owes me $4k

Seeking advice: US company owes me $4k but I'm not in the USA. We have no signed contract, but I have PayPal history and chat logs where they promised to pay

The Situation:
I am based outside USA and am trying to collect $4k from a company/person located within the United States. We do not have a formal signed contract, but we have a long-standing working relationship.

The Evidence:

Payment History: I have a clear history of previous successful payments from this company via PayPal, proving we had an active business arrangement.

Written Proof: I have saved chat logs where the debtor acknowledges that they owe me the $4k and promised to pay it

The Problem:
The person has stopped responding to my email msgs probably blocked. Since I am not a US citizen and am not currently in the US, I need advice on the best way to demand payment

Thanks