For my case I was using my own ui that means - web-js for frontend, and I was trying to setup custom login via Linkedln and was getting issues export function getApiDomain() { const apiPort = process.env.REACT_APP_API_PORT || 3001; const apiUrl = process.env.REACT_APP_API_URL || `http://localhost:${apiPort}`; return apiUrl; } export function getWebsiteDomain() { const websitePort = process.env.REACT_APP_WEBSITE_PORT || 3000; const websiteUrl = process.env.REACT_APP_WEBSITE_URL || `http://localhost:${websitePort}`; return websiteUrl; } export const SupertokenConfig = { appInfo: { appName: "Demo App", apiDomain: getApiDomain(), websiteDomain: getWebsiteDomain(), }, // recipeList contains all the modules that you want to // use from SuperTokens. See the full list here: https://supertokens.com/docs/guides recipeList: [ ThirdPartyEmailPassword.init({ signInAndUpFeature: { providers: [ { id: "linkedin", name: "Linkedin", buttonComponent: <div style={{ cursor: "pointer", border: "1", paddingTop: "5px", paddingBottom: "5px", borderRadius: "5px", borderStyle: "solid" }}>Login with Linkedin } ], }} ), Session.init(), ], }; export const recipeDetails = { docsLink: "https://supertokens.com/docs/thirdpartyemailpassword/introduction", };

I used the error handler like this https://supertokens.com/docs/passwordless/custom-ui/init/backend, still no logs

but no where in my code I made call to /signinup

so probable from core only it's getting called twice

Search for signinup in your code

it's an API that's called from the frontend to the backend

so you need to solve for that - ask in the react community please or google it