He played youth football for
Skavøypoll until 2018. In 2019 he joined
Tornado Måløy, scoring thrice for their senior team in the
2019 Fourth Division. In 2020, Skavøypoll and Tornado Måløy merged to
Måløy; also, senior football below the Second Division was not contested due to the COVID-19 pademic. After one season of youth football in Måløy, he played the next one in
Sogndal, before joining the senior squad and making his first-team debut in April 2022 against
Stabæk. When Flataker refused to prolong his contract with Sogndal, he was unceremoniously sidelined, and a transfer took place in the summer of 2025.
AIK bought the player. AIK's assistant manager described Flataker as "a role player who will fill some holes we have" and a player with "more than one X factor". Flataker was therefore ready to start AIK matches right away. In the initial phase, he became known for his lack of goalscoring, as the entire AIK team struggled with the same thing. His first goal came in the
2025-26 Svenska Cupen against
Hudiksvalls FF. He scored his first league goal against
IK Sirius in September. He then scored twice against last-placed
IFK Värnamo, who won nonetheless. ==International career==