Xbox Game Pass Spotify Offer

Sounds like it's new members only mate
https://www.xbox.com/en-GB/xbox-game-pass/pc-spotify-offer

In order to receive this Premium and Xbox Game Pass 6 Months Free Trial Offer, users must satisfy the conditions listed at 3(A)-(D) below (each an “Eligible User”). You must:

(A). be new to the Spotify Premium Service. If you have subscribed to either the Spotify Premium Service or Unlimited service or have taken a trial or introductory offer previously, you are ineligible for this offer;

(B). purchase an “Xbox Game Pass Ultimate” and/or “Xbox Game Pass for PC” subscription ( each an “Approved Product”);

(C). provide Spotify with a valid and current payment method. Neither prepaid cards nor Spotify gift cards can be used as a valid payment method for this offer; and

(D). pay for your Spotify Premium Service subscription directly to Spotify and not through a third party (e.g., not through a cable or telecommunications provider).

Eligible Users may only redeem the Premium and Xbox Game Pass 6 Months Free Trial Offer once, previous users may not redeem the offer again.

https://www.spotify.com/us/legal/Spotify-6m-Xbox-offer/

Actually the Spotify code is only for new Spotify users as well. So pre-existing accounts would not be eligible. You can find more information and the terms of the offer at https://support.xbox.com/billing/xbox-subscriptions/spotify-and-xbox-game-pass-faq

Spotify offer is only available in certain regions, specifically usa and uk, I think, and there are other eligibility criteria, which can be found at the link below

Spotify offer faq

Hi Fiveller55,

For a limited time only, new Xbox Game Pass Ultimate and Xbox Game Pass for PC (Beta) customers who reside in the US and UK will receive 6 months of Spotify Premium, subject to eligibility and the offer terms
and conditions.

Note You can’t have taken the “Xbox Game Pass $1/£1 for 1 month” offer already, and you must be new to Spotify Premium. If you subscribed to Spotify Premium or have taken a trial or introductory
offer previously, you are ineligible for this offer. Sign in to see your eligible Xbox offers.