Why does this react code always return false? [duplicate]

New to React and JS in general.

Can somebody explain why my code always returns false? is it a scoping issue?

const testforDifference = () => {
      let isDifferent = false;
      api.get("/get_mappings")
        .then((response) => {
          const result = response.data;
          if (JSON.stringify(result) !== JSON.stringify(mappings)) {
            console.log("Setting isDifferent to true")
            isDifferent = true;
          }
        })
        .catch(() => {
            console.log("error")
         });
      console.log(isDifferent)  
      return isDifferent;
    }

Am I seeing ‘Setting IsDifferent to true’ followed by ‘false’ in the console.