How do you generate a collision box to fit the mesh on an imported model

Hello, I’ve imported a model from blender, a gltf, its a big city map, so quite a complex model, is there a way I can generate a collision box on the mesh so that the charater doesn’t fall through the floor or walk through objects, I tried to open it up in the mesh editor and you can generate a box collision preset and some other stuff but I would have to create a lot of them and adjust them to each part of the map, is there a quicker way to do it where it calculates a collision box around the mesh, or else I would have to manually place invisible walls around each part of the map