'Unfortunately, lmms cannot yet use vst3. In windows You need Element by kushview for windows as a bridge in windows.
Read more here:
info https://element.readthedocs.io/
Besides that, since you are new in Forum
Welcome milo!
Here are all important links:
http://lmms.io/forum/viewtopic.php?f=1&t=4740
-A few rules and useful forum instructions
If you like to introduce yourself, to the community, go here:
http://lmms.io/forum/viewtopic.php?f=4&t=4480