seems it is still front end termination SSL/TLS addon to act as SSL/TLS
https://docs.varnish-software.com/varnish-cache-plus/features/client-ssl/ , similar to setup a nignx SSL termination for Varnish as before, hence Varnish cache itself still doesn't support https.
Even Varnish may support HTTPs in the future at some point, but LSCache has much higher performance than Varnish.
Further this question, LiteSpeed supports HTTP/3 now in product product, How about Varnish on HTTP/3?