Unfortunately..."License: OPT-175B and the smaller baseline models are made available through a
non-commercial use license agreement provided in our model license." As far as I know (so I'm not sure about this) one needs to request access to download the weights.
But the good news is that BigScience (not related to Meta) is training an 176B AI open-source AI model on the French Jean Zay supercomputer (28 petaFLOPS from multiple Nvidia A100 and V100 GPUs). The model is multilingual (trained on 1.5 TB of text, in 46 languages) and it should be ready this summer

https://huggingface.co/bigscience/tr11-176B-ml-logs