I installed flowise in render and everything worked fine. After some time this error came in the logs:
Error: ENOENT: no such file or directory, stat '/opt/render/project/src/node_modules/flowise-ui/build/index.html
This issue has been opened previously on Flowise: https://github.com/FlowiseAI/Flowise/issues/289. The suggestion is to not run this as a NodeJS native environment service but to use Docker. These are the instructions from Flowsie.