What’s the error exactly? I mean, the page asking you to upload a key or generate one. If you choose to upload one and uploaded the key.jks, what happens next?
Error: Unable to export or encrypt the private key
java.security.NoSuchAlgorithmException: Cannot find any provider supporting RSA/NONE/OAEPWithSHA1AndMGF1Padding
at java.base/javax.crypto.Cipher.getInstance(Cipher.java:574)
at com.google.wireless.android.vending.developer.signing.tools.extern.export.ExportEncryptedPrivateKeyTool.encryptPrivateKeyWithCkmRsaAesKeyWrapEncryption(ExportEncryptedPrivateKeyTool.java:284)
at com.google.wireless.android.vending.developer.signing.tools.extern.export.ExportEncryptedPrivateKeyTool.run(ExportEncryptedPrivateKeyTool.java:213)
at com.google.wireless.android.vending.developer.signing.tools.extern.export.ExportEncryptedPrivateKeyTool.main(ExportEncryptedPrivateKeyTool.java:165)