diff --git a/README.md b/README.md
index 21e7646..8e47e03 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Add Labels
 
-A GitHub Action to add labels on PR / Issue events
+A GitHub Action to add labels on PR / Issues.
 
 ## Inputs
 
@@ -8,6 +8,10 @@ A GitHub Action to add labels on PR / Issue events
 
 **Required** Labels to add.
 
+### `issue_number`
+
+**Optional** Issue/Pull Request number
+
 ## Example usage
 
 ```yaml
@@ -15,7 +19,7 @@ name: Add Label
 on:
   pull_request:
     branches:
-      - master
+      - main
     types:
       - opened
 
diff --git a/dist/index.js b/dist/index.js
index 50e5c80..1312179 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -30920,15 +30920,25 @@ __nccwpck_require__.r(__webpack_exports__);
         const octokit = (0,_actions_github__WEBPACK_IMPORTED_MODULE_1__.getOctokit)(githubToken);
         const { owner, repo } = _actions_github__WEBPACK_IMPORTED_MODULE_1__.context.repo;
         const labels = (0,_actions_core__WEBPACK_IMPORTED_MODULE_0__.getInput)("labels")
-            .split("\n")
+            .split(/[\n,]/)
             .filter((x) => x !== "");
-        const issueNumber = _actions_github__WEBPACK_IMPORTED_MODULE_1__.context.payload.number;
-        (0,_actions_core__WEBPACK_IMPORTED_MODULE_0__.info)(`Add labels: ${labels} to ${owner}/${repo}#${issueNumber}`);
+        const issueNumber = Number((0,_actions_core__WEBPACK_IMPORTED_MODULE_0__.getInput)("issue_number", { required: false }) ||
+            _actions_github__WEBPACK_IMPORTED_MODULE_1__.context.payload.pull_request?.number ||
+            _actions_github__WEBPACK_IMPORTED_MODULE_1__.context.payload.number);
+        if (isNaN(issueNumber)) {
+            (0,_actions_core__WEBPACK_IMPORTED_MODULE_0__.setFailed)("cannot find issue/PR number!");
+            return;
+        }
+        if (issueNumber <= 0) {
+            (0,_actions_core__WEBPACK_IMPORTED_MODULE_0__.setFailed)("issue/PR number should be greater than 0!");
+            return;
+        }
+        (0,_actions_core__WEBPACK_IMPORTED_MODULE_0__.info)(`Adding labels: ${labels.join(", ")} to ${owner}/${repo}#${issueNumber}`);
         await octokit.rest.issues.addLabels({
             owner,
             repo,
-            issue_number: issueNumber,
             labels,
+            issue_number: issueNumber,
         });
     }
     catch (error) {
diff --git a/src/index.ts b/src/index.ts
index 2435bf7..cfab144 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -4,6 +4,7 @@ import { getOctokit, context } from "@actions/github";
 (async () => {
   try {
     const githubToken = process.env["GITHUB_TOKEN"];
+
     if (!githubToken) {
       setFailed("GITHUB_TOKEN does not exist.");
       return;
@@ -13,18 +14,34 @@ import { getOctokit, context } from "@actions/github";
     const { owner, repo } = context.repo;
 
     const labels = getInput("labels")
-      .split("\n")
+      .split(/[\n,]/)
       .filter((x) => x !== "");
 
-    const issueNumber = context.payload.number;
+    const issueNumber = Number(
+      getInput("issue_number", { required: false }) ||
+        context.payload.pull_request?.number ||
+        context.payload.number
+    );
 
-    info(`Add labels: ${labels} to ${owner}/${repo}#${issueNumber}`);
+    if (isNaN(issueNumber)) {
+      setFailed("cannot find issue/PR number!");
+      return;
+    }
+
+    if (issueNumber <= 0) {
+      setFailed("issue/PR number should be greater than 0!");
+      return;
+    }
+
+    info(
+      `Adding labels: ${labels.join(", ")} to ${owner}/${repo}#${issueNumber}`
+    );
 
     await octokit.rest.issues.addLabels({
       owner,
       repo,
-      issue_number: issueNumber,
       labels,
+      issue_number: issueNumber,
     });
   } catch (error) {
     setFailed(error.message);