Internship Help

Hi, I'm a university student in my second year applying for internships. I received an offer from a government agency in my country that's exploding tomorrow, and it's for a 3 month internship during summer. I also have a second round interview with TikTok next week and I'm hesitant to renege. I've asked for extension with my offered company, but they only gave extra 24 hours (from tonight to tomorrow) and TikTok to expedite my decision process, but the hiring manager is away for a business trip and cannot reschedule the interview. I don't feel good about reneging since my resume was sent directly to the mentors of that agency for the project matching instead of going through the normal route since I rejected the project that I got assigned to. What would you do in my situation? Should I accept the offer and renege if I get offered or continue applying to more companies to stall for time? I'm confident I won't end up internship-less for summer even if I get none, but the quality of the roles I end up at might not be as good as either of these options.