diff --git a/package.json b/package.json
index 84cb56e..391c3d3 100644
--- a/package.json
+++ b/package.json
@@ -28,11 +28,10 @@
     "uuid": "^8.3.2"
   },
   "devDependencies": {
-    "release-it": "^15.4.1",
-    "@types/node-fetch": "^2.6.2",
     "@testing-library/dom": "^8.17.1",
     "@types/debug": "^4.1.7",
     "@types/node": "^18.6.5",
+    "@types/node-fetch": "^2.6.2",
     "@types/uuid": "^8.3.4",
     "@typescript-eslint/eslint-plugin": "^5.33.0",
     "@typescript-eslint/parser": "^5.33.0",
@@ -50,6 +49,7 @@
     "husky": "^8.0.1",
     "jsdom": "^20.0.0",
     "prettier": "2.7.1",
+    "release-it": "^15.4.1",
     "tsm": "^2.2.2",
     "tsup": "^6.2.1",
     "typescript": "^4.7.4",
diff --git a/src/APL/vercel-apl.test.ts b/src/APL/vercel-apl.test.ts
index 1938898..c004e09 100644
--- a/src/APL/vercel-apl.test.ts
+++ b/src/APL/vercel-apl.test.ts
@@ -1,7 +1,14 @@
-import { afterEach, describe, expect, it } from "vitest";
+import fetch from "node-fetch";
+import { afterEach, describe, expect, it, vi } from "vitest";
 
 import { VercelAPL, VercelAPLVariables } from "./vercel-apl";
 
+vi.mock("node-fetch", () => ({
+  default: vi.fn().mockImplementation(() => ""),
+}));
+
+const mockFetch = vi.mocked(fetch);
+
 const aplConfig = {
   deploymentToken: "token",
   registerAppURL: "http://example.com",
@@ -17,6 +24,7 @@ describe("APL", () => {
 
   afterEach(() => {
     process.env = { ...initialEnv };
+    vi.resetModules();
   });
 
   describe("VercelAPL", () => {
@@ -56,6 +64,48 @@ describe("APL", () => {
       expect(apl["registerAppURL"]).toBe("option");
     });
 
+    describe("set", () => {
+      it("Successful save of the auth data", async () => {
+        // @ts-ignore Ignore type of mocked response
+        mockFetch.mockResolvedValue({ status: 200 });
+        const apl = new VercelAPL({
+          registerAppURL: "https://registerService.example.com",
+          deploymentToken: "token",
+        });
+        await apl.set({ domain: "example.com", token: "token" });
+        expect(mockFetch).toBeCalledWith(
+          "https://registerService.example.com",
+
+          {
+            body: JSON.stringify({
+              token: "token",
+              envs: [
+                { key: "SALEOR_AUTH_TOKEN", value: "token" },
+                { key: "SALEOR_DOMAIN", value: "example.com" },
+              ],
+            }),
+            headers: {
+              "Content-Type": "application/json",
+            },
+            method: "POST",
+          }
+        );
+      });
+
+      it("Raise error when register service returns non 200 response", async () => {
+        // @ts-ignore Ignore type of mocked response
+        mockFetch.mockResolvedValue({ status: 500 });
+
+        const apl = new VercelAPL({
+          registerAppURL: "https://registerService.example.com/internalError",
+          deploymentToken: "token",
+        });
+        await expect(apl.set({ domain: "example.com", token: "token" })).rejects.toThrow(
+          "Vercel APL was not able to save auth data, register service responded with the code 500"
+        );
+      });
+    });
+
     describe("get", () => {
       describe("Read existing auth data from env", () => {
         it("Read existing auth data", async () => {
diff --git a/src/APL/vercel-apl.ts b/src/APL/vercel-apl.ts
index a529e25..843735c 100644
--- a/src/APL/vercel-apl.ts
+++ b/src/APL/vercel-apl.ts
@@ -1,5 +1,5 @@
 /* eslint-disable class-methods-use-this */
-import fetch from "node-fetch";
+import fetch, { Response } from "node-fetch";
 
 import { APL, AuthData } from "./apl";
 import { createAPLDebug } from "./apl-debug";
@@ -65,23 +65,34 @@ export class VercelAPL implements APL {
   }
 
   private async saveDataToVercel(authData?: AuthData) {
-    debug(`saveDataToVercel with: ${authData}`);
+    debug("saveDataToVercel() called with: %j", {
+      domain: authData?.domain,
+      token: authData?.token.substring(0, 4),
+    });
+    let response: Response;
     try {
-      await fetch(this.registerAppURL, {
+      response = await fetch(this.registerAppURL, {
         method: "POST",
         headers: { "Content-Type": "application/json" },
         body: JSON.stringify({
           token: this.deploymentToken,
-          envs: {
-            [VercelAPLVariables.TOKEN_VARIABLE_NAME]: authData?.token || "",
-            [VercelAPLVariables.DOMAIN_VARIABLE_NAME]: authData?.domain || "",
-          },
+          envs: [
+            { key: VercelAPLVariables.TOKEN_VARIABLE_NAME, value: authData?.token || "" },
+            { key: VercelAPLVariables.DOMAIN_VARIABLE_NAME, value: authData?.domain || "" },
+          ],
         }),
       });
     } catch (error) {
       debug("Error during saving the data:", error);
-      throw new Error(`VercelAPL was not able to save auth data${error}`);
+      throw new Error(`VercelAPL was not able to save auth data ${error}`);
     }
+    if (response.status >= 400 || response.status < 200) {
+      debug("Non 200 response code. Register service responded with %j", response);
+      throw new Error(
+        `Vercel APL was not able to save auth data, register service responded with the code ${response.status}`
+      );
+    }
+    debug("Register service responded successfully");
   }
 
   async get(domain: string) {