Convert PPK file to PEM file

follow the steps to convert PPK to PEM:

1. Launch PuTTYgen application.
2. Under File menu, click Load private key.
3. Select your .ppk file, and then choose Open.
4. Now, under the Conversions menu, click Export OpenSSH Key (force new file format).
5. Set a new name with the “.pem” extension and click the “Save” button