If the kid would rather be scrolling instagram then solve the underlying problem. They will not have a good life if they will only do anything constructive when forced to by an authority figure.
Bring kids up is not easy. There is no magic button, but its far better to solve a problem, even if its difficult, than to work around it. Forcing unengaged kids to study is like quick fixes to software that runs up technical debt,or like avoiding proper of maintenance of machinery when you it will cause more long term damage.
