https://music.apple.com/subscribe?at=1000l4QJ&ct=407&itscg=10000&itsct=407x&ls=1
That's the link I see. If it truly only offers you the Apple One plan then contact Apple about a mistaken link.
Refer to this document for ways to contact Apple ➞ Choose your country or region - Official Apple Support
Select your country (also look for "other" regions), then a product. If you don't see one that handles your issue then keep experimenting with selections until you reach one that gets you a chat session or a telephone call and get the representative to redirect you.
or:
Contact Apple for support and service by telephone ➞ Contact Apple for support and service - Apple Support
for "Billing and subscriptions" support, click here --> Subscriptions and Billing - Official Apple Support