There are two ways to export:
In xLights 3.6.x
1) Clcik Export and every channel defined in your SETUp tab would be exported. Output can be vix, vir, lms, lcvb .etc.
2) Click the Model Export" button and it prompts your which model you wanted to export. This was restricted to vie,lcb files
In xlights 4.0
1) Save your sequence. Go to CONVERT tab. Convert fseq file into lms,lcb,vir,vix
2) Right click ion the SEQUENCER tab on a model, choose export model.