If you call Get Profiles — https://developers.klaviyo.com/en/reference/get_profiles — you can add a filter with the email address, and the response will include the profile’s internal ID.

For more information please visit https://developers.klaviyo.com/en/v2024-05-15/reference/api-overview#filtering
Allowed field(s)/operator(s):
id: any, equals
email: any, equals

To add to what Salibum said, your exact GET url would look something like:

https://a.klaviyo.com/api/profiles/?filterremail]=test@example.com

 Hi there @saulblum ! 

If I can jump in with a related question about the email. Can I call the update profile request by email (rather than by profile id)?

Yes, it says it directly in the link you included. 

Legend, thats exactly what I was looking for :)