выдрал этот кусок из живого проекта
let body = { username: email, password: password, grant_type: "password" }
const searchParams = Object.keys(body)
.map(key => {
return encodeURIComponent(key) + "=" + encodeURIComponent(body[key])
})
.join("&")
await fetch(`${API_ROOT}/Token`, {
method: "POST",
headers: {
"Content-Type": "application/x-www-form-urlencoded",
Platform: Platform.OS,
buildVersion: VersionNumber.buildVersion,
},
body: searchParams,
}).then((response)=>console.log("response",response))