How to test this type of test case in angular jasmine

I am trying to test the below test case in angular jasmine

fetchTotalProjetsCount() {
return new Promise((resolve, reject) => {
  this.http.get(environment.ENV_URL + Constant.constats.endpoints.TOTAL_PROJECT_COUNT).subscribe((res: ResponseAPI) => {
    Iif (res?.statusCode === 200) {
      resolve(res)
    }
    reject()
  })
}).catch(err => console.error(err))

}