He's listed by the club as an '06 on their U16s: https://fck.de/de/spieler/u16/carl-biboum/ https://fck.de/de/spieler/u16/ Seems to be from the Virginia Beach area. https://soccer.sincsports.com/team/team.aspx?teamid=VAM05CB4 https://www.soccerwire.com/news/us-...2022-odp-national-training-camp-rosters-boys/ The combination of Va. Beach and Kaiserslautern could suggest a family military connection, but that's just a guess.
Recently moved to Elversburg per Transfermarkt. Their first team is now in the 2. Bundesliga after promotion last season. Also saw this listing from May of him being named to a DODEA "All-European" team comprised of high school athletes, so looks like Dave was spot-on with the military connection. Searched some other names on there and saw that there's another American, Max Speed, also at Elversberg.