Geo Targetly uses IP geolocation to determine visitor geolocation hence your website visitors do not need to agree to sharing their location information.
IP geolocation is a seamless process of detecting visitor geolocation and visitors will not know their location is being extracted from their IP address.
It is a seamless process because IP geolocation does not provide the exact visitor geo coordinates, instead, it provides a rough location of the visitor down to major city level.