Blocked by CORS policy: error 502

My system works for a while and then starts throwing errors in the requests from the front end to the back end. After some time, it starts accepting requests again, but then the same errors occur repeatedly. Can someone help me find a solution to make the system run stably?

thats the errors.

Access to fetch at ‘https://psicontrol-back.fly.dev/google’ from origin ‘https://psicontrol.com.br’ has been blocked by CORS policy: No ‘Access-Control-Allow-Origin’ header is present on the requested resource. If an opaque response serves your needs, set the request’s mode to ‘no-cors’ to fetch the resource with CORS disabled.

GET https://psicontrol-back.fly.dev/google net::ERR_FAILED 502 (Bad Gateway)