When I load images which I previously have worked with in LR and LRT, into LRT again, all the adjustments I did does not show up. I suppose there is an easy way to recap those adjustments, but right now I don´t know how to do this. Is there a solution?

In LR, should I just "Save metadata to file"? And then open the files in LRT?

Yes, the communication between both programs work via XMP files.
So when making changes in LR, go to Grid View, then "Metadata/Save Metadata to Files", then "Reload" in LRTimelapse.
When making changes in LRTimelapse, in Lightroom do "Metadata/Read Metadata from Files".

Ok thanks