Add extension (crx) to allowlist
Windows
*Run as administrator one of the reg-files in allowlist-downloads
If you already added extensions to the allowlist than you should change "1" to a new key (also change name of HLM-key for beta/developer versions of browsers).
Example Chrome-regfile:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome\ExtensionInstallAllowlist]
"1"="lkbebcjgcmobigpeffafkodonchffocl"