Вроде как все CRUD для nation..

front/premium_store/src/components/items/Nation/ModalNation.jsx

@@ -3,6 +3,9 @@ import axios from 'axios';
 import cl from './ModalNation.module.css';
 import '../../AddNation.css';
 
+const hostURL = "http://localhost:8080";
+const host = hostURL + "/api/1.0/nation";
+
 const ModalNation = ({data, visible, setVisible}) => {
   //для обновления уровня
   const [nation, setNation] = useState(data.nation);
@@ -17,15 +20,32 @@ const ModalNation = ({data, visible, setVisible}) => {
       rootClasses.push(cl.active);
   }
 
+  const getTokenForHeader = function () {
+    return "Bearer " + localStorage.getItem("token");
+  }
+
   //добавление новой нации
-  function updateLevel(){
+  /*function updateLevel(){
       setNation()
       axios.put('http://localhost:8080/nation/' + data.id + '?nation=' + nation + '&tankId=' + nullId)
           .then((response) => {
               console.log("Обновление нации с id " + data.id)
           });
       setVisible(false);
-  }
+  }*/
+
+  const updateLevel = async function () {
+    const requestParams = {
+        method: "PUT",
+        headers: {
+            "Content-Type": "application/json",
+            "Authorization": getTokenForHeader(),
+        }
+    };
+    const requestUrl = host + `/${data.id}?nation=${nation}&tankId=${nullId}`;
+    const response = await fetch(requestUrl, requestParams);
+    console.log("Обновление успешно!")
+}
 
   return (
       <div className={rootClasses.join(' ')} onClick={() => setVisible(false)}>
@@ -38,7 +58,7 @@ const ModalNation = ({data, visible, setVisible}) => {
               <button
                   className={cl.modalButton} 
                   type="button"
-                  onClick={updateLevel}
+                  onClick={event => updateLevel()}
               >
                   Сохранить  
               </button>

front/premium_store/src/components/items/Nation/NationItem.jsx

@@ -23,7 +23,7 @@ const NationItem = (data) => {
 
     const deleteFecth = async function (id) {
         const requestParams = {
-            method: "POST",
+            method: "DELETE",
             headers: {
                 "Content-Type": "application/json",
                 "Authorization": getTokenForHeader(),

spring_online_calculator/src/main/java/premium_store/controller/controller/NationController.java

@@ -53,7 +53,7 @@ public class NationController {
         return new FullNationDTO(nationService.updateNation(id, nation, (tankId > 0) ? tankService.findTank(tankId) : null));
     }
 
-    @PostMapping("/{id}")
+    @DeleteMapping("/{id}")
     public FullNationDTO deleteNation(@PathVariable Long id) {
         return new FullNationDTO(nationService.deleteNation(id));
     }