The United States embassy and consulate in Karachi have announced the expansion of the interview waiver eligibility program for Pakistani citizens who are currently in the process of renewing their business or B1 or B2 tourist visas. Read USA visa requirments here.
According to U.S embassy Pakistan news released on 12th January 2022, citizens of Pakistani who have valid or expired B1 or B2 visas for the last 48 months, regardless of their age are eligible for the Interview waiver eligibility program.

B1 or B2 Visa Renewal:

The renewal of B visa including categories such as 
Pakistan citizen application with a Pakistani passport 
Having U.S multiple entry visa
Application for same U.S visa class
Having valid U.S visa and applying within last 48 months before visa expiry 
Applying from same US Consulate or Embassy which issued applicant’s last visa
The last applicant before now resulted in providing and issuing U.S visa
Last U.S visa has been stolen, lost, or revoked
Applicant's previous nationality, date, and place of birth are the same for the previous and current application
Applicant complied with all United States immigration regulations and laws for his last United States visit 
Interview Waiver Applications(H1, academic J, H4, non blanket L, and F)
Applicants who had applied for Interview waiver applications include categories such as 
The applicant had a U.S visa
The applicant provided ten fingerprints at U.S Consulate General Karachi or Islamabad Embassy
Applicant's last appearance for U.S visa interview at Consulate or Embassy did not result in rejection of U.S visa
The applicant is a resident and citizen of Pakistan and is present in Pakistan at the time of application
The applicant's previous U.S visa has been lost, revoked, or stolen
Applicant’s place and date of birth are the same for previous and current applications 
The applicant is applying from the same U.S consulate or Embassy from which the visa was provided
Applicant complied with all immigration regulations and laws
The applicant had obtained an F visa and is attending the same F visas institution
The applicant had not been removed from status for a period of 3 months (J and F visas)
The applicant possessed a J visa and has a 212(e) waiver and is applying for H1B visa
Applicants box 4 (DS-2019) states as either professor, short-term scholar, university or secondary student, specialist, or research scholar (J visas).

Interview Waiver Eligibility Expansion:

Earlier only those Pakistani citizens who were 45 years of age or older were allowed to participate in the interview waiver expansion program. Moreover, the interview waiver eligibility facility has now been extended for petition-based work visa applicants and students acquiring US valid previously for the 2023 year. 
This newly launched interview waiver eligibility expansion has been launched as a procedural program in order to provide more efficient business visas and tourist renewal processes for qualified Pakistani citizens. 
Some Pakistani citizens who are eligible will still be required to make their presence known under US laws at US Consulate General or US Embassy for the required interviews after submission of visa applications. 
Pakistani citizens will also need to visit https://www.ustraveldocs.com/pk/pk-niv-visarenew.asp in order to determine whether they qualify for the interview waiver program. Moreover, Pakistani applicants who have previously scheduled their interview can now cancel their interview appointment online as they are qualified for the interview waiver program. 
Pakistani citizens can now apply under “New Application” section from the US embassy & consulate website’s scheduling dashboard and follow the provided steps online in order to submit their application for the expanded interview waiver.

Valid Pakistani Documents Verification Drop Off locations:

Pakistani citizens should only contact and approach authorized courier service locations listed at https://ustraveldocs.com/pk/pk-loc-documentdropoff.asp for submitting their interview waiver documents. Furthermore, the average applicant documents processing time is approx. four weeks.
Pakistani citizen applicants for U.S visas are recommended to visit https://www.ustraveldocs.com/pk/pk-gen-faq.asp in order to understand the required program details and related queries.