Are you talking about a shipping container? Assuming conyainer was a typo. You need to get water ans sewer to your new bathroom - however you do it.
You might want to look into a composting toilet or just set up an outhouse. Adding plumbing would be very expensive.
Hello, I found this
and this link
Do you have sewage,water,electric access?? None-You can use incinerating toilet https://incinolet.com/?_vsrefdom=adwords&gclid=EAIaIQobChMI3a3r-vPP3wIVE8NkCh0EfQuJEAAYASAAEgKA0_D_BwE or composting https://home.howstuffworks.com/green-living/composting-toilet.htm you can install water holding tank https://www.google.com/search?q=holding+tanks+for+fresh+water&rlz=1C1CHBF_enUS750US750&oq=holding+tanks+for+water&aqs=chrome.4.69i57j0l5.16842j0j7&sourceid=chrome&ie=UTF-8 system for sink use if needed for just half bath type setup. you'll still need to fill tank. https://containerhomes.net/learning-center/how-to-center/how-to-install-a-bathroom-in-a-shipping-container-home/ More info. you choose videos https://www.youtube.com/results?search_query=DIY+Shipping+container+with+bathroom
Here's add on prefab bathroom kit for containers still need plumbing,sewage electric https://www.youtube.com/watch?v=MZEkm_GiYk0