If you have experience in raising a cat, you must be patient enough to wash it yourself. You can take it to the bathroom first, close the door, let it watch you wash it, and splash less water on it from time to time to let it adapt slowly. When it doesn't react too much, hold down its neck and forelimbs with one hand, and wash its body with warm water. Don't get its head wet ~ it's best to have a hug when washing. Let the water flow out from behind the ear to avoid entering the ear, it will struggle badly ~ then dry it with a big towel immediately ~ give it something delicious after taking a shower, and it will be more convenient to wash it next time ~
Of course, it is also possible that you just won't be allowed to wash it ~ it will take a long time to cultivate feelings ~
If you want to give it a bath immediately, you can also take it to the pet hospital for a bath ~ for a physical examination ~