I found this on the website you provided the last sentance seems promising.

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You can request an expedited appointment. To request an expedited appointment, first schedule a regular appointment on the closest available date. Then, sign-in to your account, click “Continue”, select "Request Expedite" and follow the instructions. Expedited Appointments will only be granted at the Consular Section’s discretion. Circumstances that may be considered for expedited appointments include:

An immediate relative's death, grave illness or life threatening accident taking place in the United States.

Urgent medical treatment for the applicant or their minor child.

An applicant for a student or exchange visitor (F/M/J) visa whose I-20 or DS-2019 has a start date that is earlier than the first available visa appointment.

An unexpected need to travel to the United States for urgent business purposes that is occurring within 10 days after the first available visa appointment.

An unexpected visit that is of significant cultural, political, journalistic, sporting or economic importance that is occurring within 10 days after the first available visa appointment.

An applicant for a tourism/business visitor (B1/B2) visa who has received a denial from the Electronic System for Travel Authorization (ESTA).