How to format number in js and output in pug?

Question

JavaScript

Good day to all.
I pass in the object
offers
{
"id":129,
"logourl":"129.png",
"mincreditsum":7000,
"maxcreditsum":200000"
}
I want to format mincreditsum and maxcreditsum and bring them to the form 7,000 and 200,000.
I found such a regular expression. Now I output it in a loop like this
replace(/(\d)(?=(\d\d\d)+([^\d]|$))/g, '$1 ')

each offer,index in offers_arr
        span.minsumm !{offer.mincreditsum}
        span.maxsumm !{offer.maxcreditsum}

How can you use it regularly?
Now declared a function

script.
    var myFunc = function (a) {
        return a.replace(/(\d)(?=(\d\d\d)+([^\d]|$))/g, '$1 ');
    }

And I call it in a loop

each offer,index in offers_arr
     span#summin!= myFunc(offer.mincreditsum)

But it throws an error

Call to undefined function myFunc()

How will it be right?
Thanks in advance for your replies.