Regex working in every online parser but not in JS?

Question

I've created regex to parse football match score:

 (0|[1-9]\d*\s)(:)(\s0|[1-9]\d*)

When I try:

let scoreRegex = new RegExp('(0|[1-9]\d*\s)(:)(\s0|[1-9]\d*)')
scoreRegex.exec('Team One 5 : 0 Team Two') 

I get null instead of expected 3 groups. Any online parser out there validates my regex and matches the input string.

https://www.regextester.com/ +

https://regexr.com/ +

What am I missing?