Dropbox appointment - representative - do applicants need to physically sign any document physically?

Hi, we are renewing our B1/B2 visa and have gotten an visa interview waived and have dropbox appointment in March. We will be submitting the documents (DS-160 confirmation copy, visa appointment letter, original passports, original 2x2 photos) through a representative (friend/coworker).

Do the visa applicants need to sign any documents physically? or does representative need to sign anything?

Also, are there any specific instructions we should give to the representative?

Thank you

As far as I know , the applicant don’t need to sign anything. Make sure the person submitting the docs have a government issued id and provide him with the checklist of the documents being submitted.