Botpress embed website option - url parameters issue


I am facing an issue in botpress embed website.
My host : localhost:3000
I could not able to pass the url parameters as below in botpress init
Eg :
window.botpressWebChat.init({ host: 'http://localhost:3000?ref=test }) not working…

Could not able to retrieve ref params value in botpress server.

Do we have any other approach to pass the parameters in the embed view of botpress from website to botpress server.Thanks and appreciate your help.