Angular7 http.get请求不到后台服务

ngOnInit(): void {
alert(1);
this.todos$ = this.http
.get(
"http://localhost:1202/auth/api/findAll?pageNum=1&pageSize=2&appId=yq_rong360&secret=$2a$10$DKTXFeM8l/i3BtPdcuwCUeb1W/PV98qfJ7HFF.4SbJmC0nbpW5AwO"
)
.pipe(tap(console.log));
alert( JSON.stringify(this.todos$));
}

get方法请求不到后台这个是什么情况？network中也没看到有请求url