Crank up the ISO to increase shutter speed. With that lens, you want the shutter no slower than 1/300, - 1/500 or 1/1000 is better. Use a tripod when you can. When hand-holding, use good h/h technique and lean against something when possible - tree, vehicle, whatever you can find. Left hand under the lens barrel, supporting the weight, left elbow pressed tightly against body. Press shutter release gently and smoothly, don't jab at it.
https://photographylife.com/tips-on-...lephoto-lenses