After a few tries, I finally got it. Thanks to @Vaibhav who advised me for a great link in the comments. Also, I sent an email to the company Macrorify KoK-CODE and they helped me understand how an auto clicker works. Thanks! =)
I'll leave the initial solution I found here (just single click) . I'm a beginner, so maybe I did something unnecessary.
The solution is to use dispatchGesture method.
First you create a directory (I called it xml) and a file like config_accessibility_service.xml and add:
<accessibility-service
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:accessibilityEventTypes="typeAllMask"
    android:accessibilityFeedbackType="feedbackGeneric"
    android:accessibilityFlags="flagDefault"
    android:canPerformGestures="true"
    android:description="@string/accessibility_service_description"/>
And modify AndroidManifest.xml with BIND_ACCESSIBILITY_SERVICE permission:
    <service
        android:name=".AutoClickService"
        android:enabled="true"
        android:label="@string/accessibility_service_name"
        android:permission="android.permission.BIND_ACCESSIBILITY_SERVICE"
        android:exported="@string/accessibility_service_name">
        <intent-filter>
            <action android:name="android.accessibilityservice.AccessibilityService"/>
        </intent-filter>
        <meta-data
            android:name="android.accessibilityservice"
            android:resource="@xml/config_accessibility_service"/>
    </service>
My AutoClickService class:
public class AutoClickService extends AccessibilityService {
@Override
public void onCreate() {
    super.onCreate();
}
//apparently this method is called every time a event occurs
@Override
public void onAccessibilityEvent(AccessibilityEvent accessibilityEvent) {
    System.out.println("access event");
    //autoClick(2000, 100, 950, 581);
}
@Override
public void onServiceConnected() {
    super.onServiceConnected();
    autoClick(2000, 100, 950, 581);
}
@Override
public void onInterrupt() {
}
public void autoClick(int startTimeMs, int durationMs, int x, int y) {
    boolean isCalled = dispatchGesture(gestureDescription(startTimeMs, durationMs, x, y), null, null);
    System.out.println(isCalled);
}
public GestureDescription gestureDescription(int startTimeMs, int durationMs, int x, int y) {
    Path path = new Path();
    path.moveTo(x, y);
    return createGestureDescription(new GestureDescription.StrokeDescription(path, startTimeMs, durationMs));
}
public GestureDescription createGestureDescription(GestureDescription.StrokeDescription... strokes) {
    GestureDescription.Builder builder = new GestureDescription.Builder();
    for (GestureDescription.StrokeDescription stroke : strokes) {
        builder.addStroke(stroke);
    }
    return builder.build();
}
}
Finally you can verify user permission and run the service in MainActivity with:
public void checkAccessibilityServicePermission() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        int access = 0;
        try{
            access = Settings.Secure.getInt(this.getContentResolver(), android.provider.Settings.Secure.ACCESSIBILITY_ENABLED);
        } catch (Settings.SettingNotFoundException e){
            e.printStackTrace();
            //put a Toast
        }
        if (access == 0) {
            Intent myIntent = new Intent(Settings.ACTION_ACCESSIBILITY_SETTINGS);
            myIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            startActivity(myIntent);
        }
    }
}