I want to use Bolt and DOTween, but I don’t know how to make TweenCallback for Flow Graph.
UnityVS does not support callbacks natively. Look into delegate nodes from Community Addons pack. Those might do what you want, but I’m not familiar with them: GitHub - RealityStop/Bolt.Addons.Community: A community-driven project for extending Unity Bolt
People over at official discord for UnityVS will know more: Discord
Yes the add-ons will do this. In fact I already have a picture of it in use with DOTween.
You first create a Delegate Asset, and select Tween Callback as the type. Open Community Add-ons utility window, and click compile. This generates the delegate to a wrapper for UVS. Then your nodes show up for that type as Bind, Unbind, Invoke, and Create. You can get the member “callback” to get the underlying delegate, which can be used with third party.