Your language is set in your profile (upper right).
As for the 413, it means your front-end isn’t configured to accept files larger than whatever size is being sent. If you’re uploading via the Web UI, however, chunking is being used. So there is zero need to bump the body/etc sizes to 100G. The largest chunk for the Web UI will be either 10 or 100 by default (though the Desktop client will use chunk sizes up to 5000 by default). Larger files will be broken up into these chunks and take place over multiple HTTP transactions. So each upload transaction will never be larger than the chunk size.
What installation method?
Have you modified any of the chunking settings from the default?
Do you have Cloudflare in front of your deployment? If so, their free level has a 100MB limit.