Reverse Engineer Website Request Header

Hello I would like to reverse engineer a request header from this URL: https://x2y2.io/collection/doodles-official/items

The header is called: x-x2y2-signature

Please check the attached image screenshot

It seems the header it random every time the page is refreshed.

I found a reference in the source and it seems to be encypting a key but I am not sure.

Please let me know if you can assist me.