I have already changed the pose in Blender and yes, it helped. Now the model looks correct, except for one foot. One foot is normal, and the other is raised up. But that's just a matter of fine-tuning the T-pose.
edit: No, everything is correct. Everything works perfectly, the main thing is to set the T-pose properly. My problem with the leg is an addon on the animation; in it, all the models have a crooked foot.