Script

Set animator param value

public class PlayerController : MonoBehaviour
{
    private Rigidbody playerRb;
    private Animator playerAnim;

    void Update() {
        if (Input.GetKeyDown(KeyCode.Space) && isOnGround) {
            playerRb.AddForce(Vector3.up * jumpForce, ForceMode.Impulse);
            isOnGround = false;
            playerAnim.SetTrigger("Jump_trig");
        }
    }
}

Also: SetFloat, SetBool etc.