2-Cartesian fibrations

2-Cartesian fibrations I: A model for $\infty$-bicategories fibred in $\infty$-bicategories

We provide a notion of fibred in which we call 2-cartesian fibrations.We prove the existence of a left proper combinatorial simplicial model category whose fibrant objects are precisely the 2-cartesian fibrations over a chosen scaledsimplicial set over the terminal scaled simplicial set, this provides a new model structure modeling which we show is quillenequivalent to lurie s scaled simplicial set model.