Does MFA on Evident apply to API keys?
No. Enabling MFA on an Evident user will not affect the behavior of that user's API access keys.
https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000ClnFCAS&refURL=http%3A%2F%2Fknowledgebase.paloaltonetworks.com%2FKCSArticleDetail