sorry have no time yesterday.
1.1.8 are no longer supported. You should update your box.
in latest vyos. the config are like here:
https://vyos.readthedocs.io/en/latest/routing/bgp.html#route-filter
you just have to add the community with:
set policy route-map <name> rule 1 set community...
your ISP have to say how the community string have to look like.