It depends if you have pretrained models or not.

Huggingface offers a few models that are pre-trained [0], OpenNMT is a good framework [1] as is MarianMT [2]. Many of the best MarianMT models have been ported to HuggingFace.

If you don't want to self host, huggingface offers these APIs at a cost.

[0]: https://huggingface.co/models?pipeline_tag=translation [1]: https://opennmt.net/ [2]: https://marian-nmt.github.io/