wget https://docs.broadcom.com/docs-and-downloads/raid-controllers/raid-controllers-common-files/8-07-14_MegaCLI.zip
unzip 8-07-14_MegaCLI.zip
cd Linux
sudo alien MegaCli-8.07.14-1.noarch.rpm
sudo dpkg -imegacli_8.07.14-2_all.deb
/opt/MegaRAID/MegaCli/MegaCli64 -h
The repo is only for x86_amd64 binary packages.
For arm64 you have to compile from source Code by yourself for megacli or storecli. You can get the source code from github and compile the source code on your arm64 environment.
Maybe you can find preCompiled binaries for arm64 from other users