regex for picking all substring (maybe in bengali or Hindi or English) after # from a string in javascript

I have used

const regex = /#[a-zA-Z]+b/g
let text    = " Hello #river #পদ্মা #ribi"
let arr     = text.match(regex);
hashTagVal  = `${arr.toString()}`

This regex separate english alphabet but not get output the bengali word …What to do for getting that all hashtag values in output bengali, English or Hindi..Please help..