fix: Use urlencoded body for get token request

auth/token.go

@@ -2,8 +2,8 @@ package auth
 
 import (
 	"encoding/json"
-	"log/slog"
 	"net/http"
+	"strings"
 	"time"
 
 	"github.com/google/go-querystring/query"
@@ -52,20 +52,14 @@ func GetToken(params *GetTokenParams) (*Token, error) {
 		return nil, err
 	}
 
-	res, err := http.Get(TokenUrl + "?" + v.Encode())
+	res, err := http.Post(TokenUrl, "application/x-www-form-urlencoded", strings.NewReader(v.Encode()))
 	if err != nil {
 		return nil, err
 	}
 	defer res.Body.Close()
 
-	body := make([]byte, res.ContentLength)
-	if _, err := res.Body.Read(body); err != nil {
-		return nil, err
-	}
-
 	var token Token
-	if err := json.Unmarshal(body, &token); err != nil {
-		slog.Debug("failed to decode token", slog.Any("error", err), slog.String("body", string(body)))
+	if err := json.NewDecoder(res.Body).Decode(&token); err != nil {
 		return nil, err
 	}