I got an email that my iTunes Match subscription will expire.

e.g.

"Dear Diana,

Keep all your music in the cloud and listen to it anytime, anywhere.

Continue to enjoy your entire music collection in iCloud on your iOS devices, iTunes, and Apple TV. iTunes Match stores not only your songs purchased on the iTunes Store, but all of the other great music you have acquired over the years, including music from CDs.

Your subscription for iTunes Match will expire in seven days, on Apr 25, 2021. If you allow your subscription to expire, your matched and uploaded tracks will no longer be available on iCloud. To view your subscription settings and avoid interruption of your subscription, sign in to iTunes on your computer and go to your Account Information page."

I don't want to lose 15+ years worth of music uploaded into the app and purchased from Apple.

The thing is that iTunes application no longer shows up anywhere on my computer or phones. Only the iTunes Store on my phones. How do I find iTunes Match, both to use it and/or to manage my subscription?