@Sharon01, Thanks for posting in Q&A.
Currently, there are only on-premise PKI and Cloud PKI in Intune, and since you don't have the environment for on-premise AD, we suggest you try Could PKI.
https://learn.microsoft.com/en-us/mem/intune/protect/microsoft-cloud-pki-overview
Before that, please contact Cisco to ask if the authentication method of cloud is supported, if so, you can issue the certificate through Cloud PKI and verify the certificate through SCEP profile.
Hope it will help.
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