Hi there @willo,
Welcome to the Community and thanks for posting your question here! We appreciate all opportunities to share info as well as learn from each other.
To get a general understanding for others, Klaviyo is able to identify and automatically set a profile's location by using the geo-IP location when a contact is identified/cookied. For example when a contact fills out a signup form, clicks on a Klaviyo email, etc. In addition, if someone has made a purchase, the billing address shared as part of the Placed Order event will be used as the verified source for a contact's location.
Unfortunately, there isn't a way to manually set a contact's location using geo-IP location. For now, you could actually manually set a contact's location using a .CSV import. I will gladly put this in as a product request so that our team has eyes on this as an idea for an upcoming potential feature! It seems like a great idea and I can see how it might be very beneficial to have one.
Here are also two great community posts that also go into how Klaviyo and geo-IP location works!
All the best,
Alex