Inbound OAuth enablement issue- JWT token flow

[Wasif]

We are evaluating the different flows to enable OAuth authentication for our REST APIs.
We evaluated some OAuth flow options and now we are evaluating the JWT flow for Inbound OAuth referred in the ServiceNow documentation:

SN Doc: https://docs.servicenow.com/bundle/vancouver-platform-security/page/administer/security/task/create-...

We reviewed one support detailed documentation elucidating the detailed steps to have the certificate setup in place, but importing the certificates in ServiceNow is giving issues and we are not able to go past 2nd step to check the JWT token option for OAuth.

SN Support Doc: https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB1275215

Where we got stuck::
1. We generated a Java keystore and a .keystore file was created.
2. Now when we are trying to import this ".keystore" file into the SN application. It throws an error as mentioned in "javaKeystoreFileError.png"
3. FYI- we have added this file type in the list of valid attachment extensions (property: glide.attachment.extensions), but still the impediment exists
4. Just to bypass the error we even made one property as false to not check the MIME type (which is not recommended) to see if we can proceed further with the setup (Property: glide.security.file.mime_type.validation)
5. But later when we have to upload the PEM file in one other step- it failed here as well. Refer 'pemCertificateInvalidFormat.png'

Can someone please help how to progress from this impediment?

[PVJShareKnowled]

Please try to save the certificate in .crt format and try.

[Wasif]

Did not work. Already tried that earlier