To convert an SSH key from PEM format to PPK format, you can use PuTTYgen:
1. Install and open PuTTY.
2. Click the Load button and select the PEM file with the key you want to convert.
3. PuTTYgen will prompt you to confirm that you want to import the key. Click OK.
4. Click the Save private key button.
5. Save it on your device for future use.