https://dl.akr-developers.com/?file=skkk/TWRP/A12/v6.3_A12/%5BREC_BOOT%5D3.6.2_12-RedmiK30SUltra-Mi10T%5BPro%5D_v6.3_A12-apollo-skkk_dc4ecad7.zip
For instructions how to install it you can check this forum or use google.
Good luck!
This is a forum for xiaomi.eu rom based on china rom. But you should try to flash latest fastboot rom with MiFlash - search google for guides.
Note: Choose Clean all and not Clean all and lock in lower right corner of MiFlash.
Good luck, werty
Bear in mind that Redmi K30S Ultra is equivalent to Mi 10T only. In the beginning the roms were unified for both Mi10T and Pro but Xiaomi has probably made some changes that by coincidence affect the pro variant but even they can't be blamed as in fact they don't have the device. So...