If you're an international medical graduate (IMG) applying for residency this year, I'd recommend you take a look at the Educational Commission for Foreign Medical Graduates® (ECFMG) ERAS Support for Residency main page. There, you can find eligibility requirements, an overview of the IMG application process, a timeline, and details regarding which documents ECFMG ERAS Support Services will upload for candidates and what your obligation is regarding those documents.
There's also technical guidance for your letter of recommendation writers, so you can direct them to online instructions through the Support for Residency main page.