If you’re having trouble getting your dog into the crate or your dog fights you a lot then you have not properly trained your dog to use the crate.
First of all remember that you should never push or shove your dog into the crate. They must want to go into it naturally at first. Remember being locked up in a small space is scary even for dogs so you have to help them overcome this fear.
Before you start crate training, place the crate in the middle of the room with the door open. Just leave it there for a few days for your dog to get used to its smell and being around it. You can even play some toys around it and even some treats.
After a while place more and more treats inside the crate allowing your dog to go in there to get them. Only after your dog is comfortable being around a crate and going into the crate, can you proceed closing the door behind them.
To do this, ask your dog to go into the crate and sit or use the stay command. Try to get them to stay for at least five minutes before they come out.
Next try closing the door during those five minutes and see if your dog still behaves. You might only have them stay for one minute initially.
Just start in small increments of time and slowly work up. Eventually your dog should see the crate as a safe place to be.
If your dog is barking a lot in the crate or refuses to go into the crate start the crate training process over again, but this time go very slow.