Is it possible to parse request headers?

I have zero knowledge with javascript. This line is what I’m trying to figure out.

 let Q = (() => {
                    class e {
                        constructor(e, t, n, i, r, s, o) {
                            this.authService = e, this.cache = t, this.dialog = n, this.storage = i, this.transferState = r, this.platformId = s, this.environment = o
                        }
                        intercept(e, t) {
                            if (Object(i.C)(this.platformId) && (e.url.includes("cart") || e.url.includes("token"))) return R.a;
                            "string" != typeof this.authService.getToken() || e.url.includes("token") || e.url.includes("https://ipv4.jsonip.com/") || (e = e.clone({
                                setHeaders: {
                                    Authorization: "Bearer " + this.authService.getToken()
                                }
                            })), "string" == typeof this.authService.getCaptchaToken() && (e = e.clone({
                                setHeaders: {
                                    **RECAPTCHA**: "" + this.authService.getCaptchaToken()
                                }
                            }));

The RECAPTCHA one. Can anyone please point me to the right direction.