EAD problem

My guess is you have to include 1) a copy of your I-140 approval notice and 2) a photo ID issued by federal or State agency. The photo ID must be color copy or orginal copy. Passport or driver license is fine. Whatever "request further evidence" is, it won't be too difficult to handle it, in addition, you'll be asked to submit the RFE in a matter of month or even longer time. So, secure your job and you'll see USCIS specified RFE within less than a week. Good luck.