To apply a patch in Magento 2, you can follow these steps:

Step 1: Understand Patch Files
Patches in Magento 2 are usually provided as `.patch` files. These files contain the differences between the original code and the patched code. Before applying a patch, it’s essential to understand the purpose and impact of the patch. The patch file may come with instructions or release notes that provide additional information, read these before applying the patch.

Step 2: Backup Your Magento Installation
Before applying any patch, it’s highly recommended to create a backup of your Magento installation. This allows you to restore your website to its previous state if anything goes wrong during the patching process.

Step 3: Download the Patch File
Obtain the patch file from the official Magento website, a trusted source, or the vendor providing the patch. Make sure to download the patch file that corresponds to your Magento version.

Step 4: Transfer the Patch File to Your Magento Server
Using FTP or other file transfer methods, upload the patch file to your Magento server. Place the patch file in the root directory of your Magento installation.

Step 5: Run the Patch Command
Access your server via SSH or Command Line Interface (CLI) and navigate to the root directory of your Magento installation.

Run the following command to apply the patch:

“`shell
patch -p1 < patch_file_name.patch
“`

Replace `patch_file_name.patch` with the actual name of the patch file you uploaded.

Step 6: Verify the Patch Application
After running the patch command, the patch will be applied to your Magento installation. It’s essential to verify that the patch has been successfully applied.

Review the command output for any error messages or warnings. If the patch application is successful, you should see messages indicating the patched files.

Step 7: Clear Cache
To ensure that the patched changes take effect, clear the Magento cache. Run the following command from the root directory of your Magento installation:

“`shell
php bin/magento cache:clean
“`

Step 8: Test the Patch
After applying the patch and clearing the cache, thoroughly test your Magento store to ensure that the patch has resolved the issue it was intended to fix. Verify that the expected functionality is working correctly and that there are no new issues introduced by the patch.

Congratulations! You have successfully applied a patch in Magento 2. Remember to keep a record of the applied patches for future reference, and regularly update your Magento installation with the latest patches and updates provided by Magento or third-party vendors to ensure the security and stability of your store.