Who insisted on riding on the sled in call of the wild?

In "The Call of the Wild" by Jack London, Buck's desire to ride on the sled is primarily insisted upon by Manuel, who initially sells him to a group of dog traders. However, once he is part of the sled team, Buck's strength and leadership qualities emerge, leading him to take on a prominent role in guiding the sled. Throughout the story, Buck's experiences and instincts ultimately shape his evolution from a domesticated pet to a wild creature, allowing him to embrace his true nature.