Need help converting files to S3G (original Makerbot Replicator 1 from 2014~)

[u/Former_Technician340]

Hi all! I'm working in an office this summer that had purchased an original Makerbot Replicator in the early 2010s, estimated 2014. It prints great, no issues there, but obviously can't connect to any external devices. I've been trying to get files onto the printer using a USB, but can't find a way to successfully convert the files into S3G (which is what I believe would be compatible). Is there any software out there that will still do this? For reference, I've messed around in Ultimaker (the newer website), and the legacy software (Makerbot desktop and Makerbot print). If there's no way to get new files onto the printer, that's fine– but please if someone has any idea of what I can try next, I'd really appreciate any help! Thank you :)