Hi @Mikayel Mikayelyan ,
Good day.
Since you're going to upgrade from CU9 to CU23, there is a huge gap of them.
You should install the .Net FrameWork .4.8 to support the CU23.
Also if you want to use the PowerShell to upgrade, you'll have to make your Schema/AD/AD domain prepared, If you use the Setup Wizard, you don't have to do this.
For this issue, you can give a full control permission of the folder to your account or add Everyone to the list and give it Full Control.
A related case that could help: Exchange 2019 CU8 Upgrade failed - insufficient privileges to access \owa\auth\15.2.792
Regards,
Zhengqi Lou
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