What JavaScript code is needed in GTM to pass the Google Analytics cookie?

Question

JavaScript

Good afternoon!
Please tell me how to deal with this situation: you need to organize the transfer of the order traffic source to 1C, for this we want to parse the Google Analytics cookie “__utmz”, respectively, pull out the traffic source.
On the GTM site, only "_ga" is passed the cookie. What JavaScript code needs to be configured in GTM in order for the “__utmz” cookie to start being transmitted? Thanks in advance for your reply.