This device was originaly supported until android 11, then only unofficial during some years,
[UNOFFICIAL BUILD] Xiaomi Note 8T (ginkgo) for /e/OS-T - #25
[UNOFFICIAL BUILD] Xiaomi Note 8T (ginkgo) for /e/OS-U - #22
but it is now supported again, here are e-3.x-a15-community builds
/e/OS community ginkgo download
Install /e/OS on a Xiaomi Redmi Note 8 / 8T - “ginkgo”